JPS634196B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic accompaniment device for an electronic musical instrument, and more particularly to an apparatus for performing start-stop control of rhythm pattern generation using a keyboard without using a special switch.

In conventional electronic musical instruments, the following method was used to stop the rhythm pattern generation operation for automatic accompaniment. One method is to manually turn off the rhythm start/stop switch provided on the front panel of the electronic instrument housing, and the other method is to manually turn off the rhythm start/stop switch provided on the front panel of the electronic instrument housing. This is a method of pressing with the tip. With the former method, if you want to stop the rhythm pattern generation operation while playing the keyboard, you have to extend your right or left hand over the keyboard to the rhythm start/stop switch position to turn off the switch. This has the disadvantage of interfering with performance operations. In this regard, although the latter method does not interfere with manual keyboard performance, it is necessary to press the foot switch with the same foot while operating the expression pedal, making it difficult for inexperienced beginners to operate the foot switch. The problem is that it is difficult. Another disadvantage is that the expression pedal must be provided with a foot switch, which increases manufacturing costs.
Furthermore, tabletop electronic instruments that do not have an expression pedal cannot be equipped with a foot switch, so they must rely on the rhythm start/stop switch, which interferes with manual keyboard performance. I didn't get it.

On the other hand, using a keyboard to control the start/stop of a rhythm is shown in Japanese Utility Model Application Publication No. 52-46816, but in this case, a switch to change the function of a specific key is essential.
There were problems in that the configuration was complicated and the cost was high. Also, the start of the rhythm/
The key that can perform stop control is not any key on the keyboard, but only one specific key, so there is a problem that there is a limit to operability and it is easy for beginners and other inexperienced users to operate incorrectly. . Furthermore, since the specific key becomes a key exclusively for start/stop control, it is absolutely impossible to use that key as both a start/stop control key and a musical tone performance key during rhythm performance, which may interfere with the performance. There was also the problem that there was a risk of causing

This invention was made in view of the above points,
By using the keyboard to perform rhythm start/stop control, it is possible to stop (and even start) the rhythm pattern generation operation without relying on a special switch such as a rhythm start/stop switch or a foot switch. At the same time, it also addresses the conventional problems caused by using a keyboard (i.e., an extra switch is required, it is easy to misoperate, and it is difficult to start/start.
An object of the present invention is to provide an automatic accompaniment device for an electronic musical instrument that solves the problem that keys used for stop control cannot be used as musical tone performance keys.

For this purpose, the automatic accompaniment device for an electronic musical instrument according to the present invention includes a pressed-key number detection circuit that detects the number of keys pressed simultaneously on a keyboard, and when the detection circuit detects a predetermined number of pressed keys or more, the rhythm A start/stop control circuit for starting or stopping the operation of the pattern generation circuit, and a sound generation inhibiting means for inhibiting the sound generation of the automatic accompaniment tone while the detection circuit detects a predetermined plurality of key presses or more. It is characterized by this.

When a predetermined plurality of keys or more are pressed during automatic accompaniment performance, a start/stop control circuit controls the rhythm pattern generation circuit to start or stop its operation. At the same time, the generation prohibition means prohibits the generation of automatic accompaniment sounds. On the other hand, when fewer than the predetermined number of keys are pressed, automatic accompaniment sounds corresponding to the keys are produced.
In this way, automatic accompaniment start/stop control is performed on the condition that the key press operation is a predetermined plurality of keys or more that are not mapped to produce automatic accompaniment sounds, and such key press operation A feature of the present invention is that the generation of automatic accompaniment sounds is sometimes prohibited. Therefore, there is no need for a special changeover switch, and since any key can be operated as long as it is a predetermined number or more, there is no problem of erroneous operation, and during that time, the generation of automatic accompaniment sounds is prohibited. This eliminates the problem of mispronunciation, and any key can be used for musical tone performance (automatic accompaniment tone performance).

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an embodiment of the present invention in an analog electronic musical instrument, and the keyboard section consists of a melody key area 10 and an accompaniment key area 11. If the keyboard section of this electronic musical instrument is made up of a single-row keyboard, generally a predetermined high-pitched key range is used as the melody key range 10, and a predetermined low-pitched key range is used as the accompaniment key range 11. . The accompaniment key area 11 is normally used to specify accompaniment chords, but in this embodiment it is also used to control the start and stop of rhythm pattern generation operations. That is, by simultaneously pressing a predetermined number or more keys in the accompaniment key area 11, rhythm pattern generation can be started or stopped. For this purpose, a key press number detection circuit 12 and a start/stop control circuit 13 controlled by the output of this circuit 12 are provided.

The pressed key number detection circuit 12 is a circuit for detecting that a predetermined number or more keys, which instruct the start or stop of rhythm pattern generation, are simultaneously pressed in the accompaniment key area 11. In normal chord performance in the accompaniment key area 11, the 3
Since 4 to 4 keys are pressed at the same time, the number of keys pressed for instructing the start/stop of rhythm pattern generation is set to a larger number (for example, 5 keys). In this example, the number of simultaneous key presses for instructing the start/stop of rhythm pattern generation is determined to be five or more. Therefore, the number of pressed keys detection circuit 12
In this case, when five or more keys are pressed at the same time in the accompaniment key area 11, a five-key press detection signal 5K is generated.

The start/stop control circuit 13 applies a rhythm start signal RS to the enable input (EN) of the rhythm pattern generation circuit 14. The rhythm pattern generation circuit 14 enters a rhythm pattern generation enabled state (start state) when the rhythm start signal RS applied to the enable input (EN) is "1".
When it is "0", a rhythm pattern cannot be generated (stop state). The start/stop control circuit 13 outputs the rhythm start signal RS when the 5 key press detection signal 5K is given from the key press number detection circuit 12.
, and thereby controls the start or stop of rhythm pattern generation.

Before providing a detailed explanation of the key depression number detection circuit 12 and the start/stop control circuit 13, the overall structure of the analog electronic musical instrument shown in FIG. 1 will be briefly explained.

The opening/closing circuit 15 of the melody key area 10 derives the sound source signal corresponding to the key pressed in the melody key area 10 from the melody sound source circuit 16, gives it an envelope, and supplies it to the melody tone circuit 17. The melody sound signal whose timbre is controlled by the timbre circuit 17 reaches a sound system 18 and is produced.

The opening/closing circuit 19 for the accompaniment key area 11 derives a sound source signal corresponding to the key pressed in the accompaniment key area 11 from the accompaniment sound source circuit 20 . Further, each key switch output of the accompaniment key area 11 is input to a chord detection circuit 21. The chord detection circuit 21 detects a chord based on the combination of keys pressed in the accompaniment key area 11, and outputs root note data RT indicating the root note of the detected chord. For example, the root note data RT is 12
It consists of 12 lines corresponding to note names, and only the single line corresponding to the root note name of the detected chord is "1" and the others are "0". Note that the chord detection circuit 21 performs the above-described chord detection operation in the "finger chord mode", and performs a single note selection operation in the "single finger mode". "Single Finger Chord Mode" is a mode in which all the keys corresponding to the constituent notes of a desired chord are pressed in the accompaniment keyboard area 11, and all the keys pressed are sounded as an accompaniment chord. This is a mode in which a key corresponding to the root note of a desired chord is pressed in the accompaniment key area 11, and chord constituent notes are automatically created and produced based on the root note. The switch FC-SW, which is linked to the mode changeover switch FC/SF-SW, is turned on as shown in the figure when in the "fin guard chord mode", and the chord detection circuit 2
1 to perform a chord detection operation. In the "single finger mode", the switch FC-SW is turned off, causing the chord detection circuit 21 to perform a single note selection operation. The single note selection operation is, for example, the lowest note (or highest note) selection operation, which selects the lowest note (or highest note) of the pressed key in the accompaniment key area 11, and selects the root corresponding to the selected single note name. Output sound data RT.

The opening/closing circuit 22 is a circuit that performs opening/closing control of a plurality of sound source signals having a predetermined pitch relationship based on the root note data RT. That is, among the sound source signals corresponding to each note name given from the accompaniment sound source circuit 20, the sound source signal of the note name (root note name) indicated by the root note data RT is derived once to the note line 1, and then Deriving the sound source signal of the pitch name a minor third above the pitch name indicated by the sound data RT to the minor third tone line 3 ^b ,
The sound source signal of the pitch name above the major third is derived to the major third line 3, the sound source signal of the pitch name above the perfect fifth is derived to the fifth pitch line 5, and the sound source signal of the pitch name above the minor seventh is derived. The signal is derived to minor seventh line ^7b . The sound source signals of each line 1 to ^7b are input to the SF chord constituent tone selector 23, and the tone source signals of the 1st tone line 1 and the 5th tone line 5 are input to the bass tone selector 24.

The SF chord constituent note selector 23 is for selecting the sound source signal of the constituent notes of an accompaniment chord in accordance with the chord type in the "single finger mode". As a chord type selection means in single finger mode, for example, the minor chord selection switch min-
SW and a seventh chord selection switch 7th-SW are provided. Switch min for major chords
-SW and 7th-SW are both turned off, and in the SF chord constituent tone selector 23, 1st note line 1, major 3rd
The sound source signals of degree line 3 and fifth degree line 5 are selected and mixed and output. In the case of a minor chord, turn on the switch min-SW, select the sound source signals of 1st note line 1, minor third note line 3 ^b , and 5th note line 5 in the SF chord constituent tone selector 23, and output the mixture. . In the case of a seventh chord, switch 7th-SW is turned on, and the sound source signals of 1st note line 1, major 3rd note line 3, and minor 7th note line ^7b are selected and mixed and output.

The output of the opening/closing circuit 19 and the output of the SF chord constituent note selector 23 are connected to the mode changeover switch FC/SF-.
SW, and one of them is selected depending on the state of the switch FC/SF-SW and inputted to the chord generation gate 25. In the case of "fin guard chord mode", the switch FC/SF-SW is connected to the opening/closing circuit 19 as shown in the figure, and the sound source signals of all the keys pressed in the accompaniment key area 11 are sent to the chord sounding gate 25. is input. In the case of "single finger mode", switch FC/SF-SW
Contrary to the illustration, is connected to the side of the SF chord constituent tone selector 23, and the sound source signal of the automatically selected chord constituent tone is inputted to the chord generation gate 25 via the opening/closing circuit 22 and the selector 23.

A chord sounding timing pattern pulse CT is applied from the rhythm pattern generating circuit 14 to the gate control input of the chord sounding gate 25, and a chord sound source signal is selectively derived in accordance with the generation timing of this pulse CT, and an envelope is added to the chord sound source signal. It is supplied to the chord tone color circuit 26.

On the other hand, the bass sound selector 24 receives the bass pattern data BPD from the rhythm pattern generation circuit 14.
is given, and the selector 24 selects the sound source signal having the pitch indicated by the base pattern data BPD. In this example, the base pattern data BPD is designed to indicate one of the first to fifth sounds. Line 1 when base pattern data BPD is “1”
The sound source signal of the one-degree sound is selected by the selector 24,
When the value is "0", the sound source signal of the fifth tone on line 5 is selected by the selector 24. Bass sound selector 24
The sound source signal of the 1st or 5th tone selected in is applied to the octave frequency dividing circuit 27, and is lowered by an appropriate octave (for example, one octave) until it reaches a predetermined bass range.

The bass sound source signal output from the octave frequency dividing circuit 27 is input to the bass sound generation gate 28. A bass sound generation timing pattern pulse BT is given from the rhythm pattern generation circuit 14 to the gate control input of the bass sound generation gate 28, and a bass sound sound source signal is selectively derived in accordance with the generation timing of this pulse BT, and the envelope It is given and supplied to the bass tone color circuit 29.

Musical tone signals of chords and bass tones to which predetermined tones have been applied by the tone color circuits 26 and 29, respectively, are applied to the sound system 18 and are produced.

The rhythm pattern generation circuit 14 includes a rhythm selection means (not shown) and pattern data corresponding to the selected rhythm (pronunciation timing pattern pulse PT for each percussion instrument, base pattern data BPD, bass tone pronunciation timing pattern pulse BT, chord pronunciation). It includes a read-only memory (not shown) that reads out timing pattern pulse CT, etc.) according to the basic tempo clock pulse TEMPO, etc.
When the rhythm start signal RS given from the start-stop control circuit 13 is "1", reading (generation) of each of the pattern data described above becomes possible, and when the signal RS is "0", reading is stopped.
The basic tempo clock pulse TEMPO is generated by a variable clock pulse generator 30. The sound generation timing pattern pulse PT for each percussion instrument is applied to the rhythm sound source circuit 31, and the sound source signal of the percussion instrument generating the pulse PT is generated from the rhythm sound source circuit 31 in accordance with the pulse generation timing.

FIG. 2 is a diagram showing a detailed example of the key depression number detection circuit 12 and the start/stop control circuit 13. The pressed key number detection circuit 12 is provided with key switches KS ₁ to KSn that operate in conjunction with each key in the accompaniment key area 11 . Resistors R ₁ to Rn having the same resistance value (r ₁ ) are connected in series to each key switch KS 1 to KSn, and the other ends of each of _{the resistors R 1 to} Rn are commonly connected to a resistor Rm. There is. When a key is pressed in the accompaniment key area 11, the key switch corresponding to the pressed key is activated.
KS ₁ to KSn are turned on, and a parallel circuit consisting of resistors R ₁ to Rn corresponding to the number of pressed keys is formed. Since the resistance values (r ₁ ) of the resistors R ₁ to Rn are equal, if the number of pressed keys is N, the combined resistance value of the parallel circuit is r ₁ /N. Therefore, the common connection point 32 of the resistors R ₁ to Rn
The voltage Vkey extracted from is expressed by the following equation.
Note that the value of the resistor Rm is defined as _r2 , and the voltage applied to the circuit is defined as V.

Vkey=r ₂ /r ₂ +r ₁ /N·V (1) As is clear from the above equation, an analog voltage Vkey corresponding to the number N of pressed keys is obtained from point 32.
A voltage Vkey corresponding to the number of keys pressed is input to analog comparators 33 and 34. The analog comparator 34 is a circuit for detecting a predetermined number of pressed keys, that is, five or more keys pressed for rhythm pattern start/stop control. The analog comparator 33 is a circuit for detecting that some key is pressed in the accompaniment key area 11. Since the comparator 33 is for detecting that some key has been pressed, that is, that one or more keys have been pressed, its comparison reference voltage Vref ₁ is determined to satisfy the following condition.

0<Vref ₁ <r ₂ /r ₂ +r ₁・V ...(2) (r ₂ /r ₂ +r ₁・V) is the value of the voltage Vkey when the number of pressed keys N is 1, and the reference voltage Vref ₁ is set to a value greater than 0 and smaller than the value of the voltage Vkey when the number of pressed keys is 1. Therefore, accompaniment key area 1
When some key is pressed at 1 (the number of keys pressed is 1 or more), "Vref ₁ <Vkey" and the output of the comparator 33 becomes "1". The output “1” of this comparator 33 is any key-on signal AKO
The signal is input to the start/stop control circuit 13 as a signal.

The reference voltage Vref ₂ of the comparator 34 is determined to satisfy the following conditions.

r ₂ /r ₂ +r ₁ /4・V<Vref ₂ <r ₂ /r ₂ +r ₁ /5・V…(
3) (r ₂ / r ₂ + r ₁ /4・V) is the value of voltage Vkey when the number of keys pressed N is 4, and (r ₂ / r ₂ + r ₁ /5・V) is the number N of keys pressed is the value of voltage Vkey when is 5.
Therefore, when five or more keys are pressed simultaneously in the accompaniment key area 11, "Vref ₂ <Vkey" and the output of the comparator 34 becomes "1". This comparator 3
The output "1" of 4 is inputted to the start/stop control circuit 13 as the 5th keystroke detection signal 5K.

In the example of FIG. 2, the start-stop control circuit 1
3 is the rhythm start/stop switch START/
It is equipped with a STOP and a synchronized start switch SYNC, and the start control of rhythm pattern generation is performed based on the operation of this switch START/STOP or SYNC, and the stop control is performed based on the 5 key press detection signal 5K.

Rhythm start/stop switch START/
If you want to start the rhythm with STOP, turn on the corresponding switch START/STOP, and then
Turn off SYNC. Switch START/STOP
When turned on, one differential pulse is outputted from the differentiating circuit 35 and applied to the set input S of the flip-flop 37 from the OR circuit 36. As a result, the flip-flop 37 is set, and its output Q rises to "1". This flip-flop 37
The output Q is applied as the rhythm start signal RS to the enable input EN of the rhythm pattern generation circuit 14 (FIG. 1). Therefore, by setting the flip-flop 37, the rhythm start signal RS rises to "1", thereby enabling the rhythm pattern generation circuit 14 and starting the rhythm.

Turn on the synchronized start switch SYNC to start the rhythm (synchronized start) in synchronization with the first key press. At this time the switch
Turn START/STOP off. switch
When SYNC is turned on, a signal "1" is input from the switch SYNC to the AND circuit 38. When a normal chord performance starts in the accompaniment key area 11, the any key-on signal AKO is generated, and the AND circuit 3
8 is input. In normal chord performance, five or more keys are not pressed at the same time, so at this time, the five-key depression detection signal 5K is "0". A signal “1” obtained by inverting this signal 5K by an inverter 39 is applied to the remaining inputs of the AND circuit 38. Therefore, the condition of the AND circuit 38 is established in synchronization with the first chord key press, and the flip-flop 37 is set via the OR circuit 36, resulting in a rhythm start state.

When a rhythm pattern occurs (rhythm start signal
When 5 or more keys are pressed simultaneously in the accompaniment key area 11 (when RS is "1"), the 5 key press detection signal 5K becomes "1" and the flip-flop 37 is output via the OR circuit 40 as described above. Applied to reset input R. As a result, the flip-flop 37 is reset and the rhythm start signal RS falls to "0". Therefore, the rhythm pattern generation circuit 14
(Fig. 1) becomes inoperable, and various rhythm pattern data (RT, BPD, BT, CT, etc.) are no longer generated. In addition, at this time, any key on signal
Although AKO is also generated, the output of the inverter 39 which inverts the fifth keystroke detection signal 5K is "0", and the condition of the AND circuit 38 is not satisfied.

Rhythm start/stop switch START/
When both STOP and synchronized start switch SYNC are turned off, the outputs of inverters 42 and 43 become "1", and the condition of AND circuit 41 is satisfied.
"1" is applied from the AND circuit 41 to the reset input R of the flip-flop 37 via the OR circuit 40. Therefore, this switch START/
The rhythm pattern can be stopped by turning off STOP and SYNC. However, with this invention, the rhythm pattern can be stopped simply by pressing five or more keys in the accompaniment key range 11 that have been played up until now, without having to reach for the START/STOP or SYNC switches. is easy.

FIG. 3 is a diagram showing another detailed example of the start/stop control circuit 13, showing an example in which both rhythm start and stop are controlled based on the 5th keystroke detection signal 5K. In this example, a synchronized start function is not provided, and a synchronized start switch SYNC as shown in FIG. 2 is not provided. Therefore, any key-on signal AKO is also not used.

In FIG. 3, when the rhythm start/stop switch START/STOP is off, the output of the inverter 44 is "1", and the T-type flip-flop 45 is always reset. switch
When START/STOP is turned on, inverter 44
The output of the flip-flop 45 becomes "0" and the reset of the flip-flop 45 is released. At the same time, the switch
“1” is applied to the AND circuit 46 from START/STOP. The other input of the AND circuit 46 receives a 5-key press detection signal 5K from the key press number detection circuit 12 (FIGS. 1 and 2). Switch START/
After turning on STOP, if five or more keys are pressed simultaneously in the accompaniment key area 11, the five key press detection signal 5K becomes "1", and the AND circuit 46 gives "1" to the T input of the flip-flop 45. As a result, the state of the flip-flop 45 is inverted from "0" to "1", and the output Q, that is, the rhythm start signal RS rises to "1". In this way, a rhythm pattern can be started based on key depression operations of five or more keys in the accompaniment key area 11.

When the state of the flip-flop 45 is "1", that is, the rhythm start signal RS is "1", if five or more keys are pressed simultaneously in the accompaniment key area 11, the five key press detection signal 5K becomes "1" again, and the AND circuit 46
The output of becomes “1” and the T-type flip-flop 4
The state of 5 is reversed from "1" to "0". As a result, the rhythm pattern is stopped.

FIG. 4 is a diagram showing an embodiment in which the present invention is applied to a digital electronic musical instrument. Although the gist of the present invention is the key press number detection circuit 12A and the start/stop control circuit 13A, the overall configuration of the electronic musical instrument shown in FIG. 4 will be explained first.

The electronic musical instrument shown in FIG. 4 is of a single-keyboard type, and a key switch matrix 47 has key switches arranged in a matrix that correspond to each key of the single-level keyboard. The key scanning circuit 48 sequentially scans each key switch of the key switch matrix 47,
Time-division multiplexed key data that indicates whether a key is on or off based on the presence or absence of a pulse (“1” or “0”) in the time slot corresponding to each key.
Output KTDM to a single output line. Scanning in the key scanning circuit 48 is controlled by a scanning counter 49. The scanning counter 49 counts the clock pulse φ _A given from the timing signal generation circuit 50, and includes a note counter section 49A that uses the clock pulse φ _A as a count pulse, and an octave counter that uses the carry-out signal of this note counter section 49A as a count pulse. Part 4
It consists of 9B.

The single-stage keyboard has the lowest key C2 to the highest key C7.
It is equipped with 61 keys, 13 keys from keys C2 to C3 are used as the accompaniment key range LK, and 48 keys from keys C#3 to C7 are used as the melody key range UK. The key scanning circuit 48 is configured to scan keys in order from the treble side. That is, the scanning counter 49 outputs key codes KC in order of high notes from the highest key C7 to the lowest key C2, and the key scanning circuit 4
8, the highest key C7 to the lowest key C2 correspond to the key code KC given from this scanning counter 49.
Scan each key switch in turn until .

The key code KC consists of a combination of a 4-bit note code NC output from the note counter section 49A and a 3-bit octave code OC output from the octave counter section 49B. Note code output from note counter section 49A
As shown in FIG. 5b, the contents of NC change in the order of high notes from the highest note name C to the lowest note name C# every time the clock pulse φ _A is applied. The key switch corresponding to the note name of this note code NC is scanned by the key switch matrix 47. Every time the note counter 49A counts 12, the octave counter 49B counts 1. That is, when the contents of the note counter section 49A change from the lowest note name C# to the highest note name C, the contents of the octave counter section 49B change. As shown in FIG. 5c, initially, the octave range indicated by the octave code OC output from the octave counter section 49B is the highest octave OC from key C7 to C#6.
5, and at this time, the signal BT0 becomes "1".
Hereinafter, as shown in FIG.
Every time NC is counted, the contents of the octave code OC in the octave counter section 49B change sequentially from one octave lower, OC4 to OC.
0, and accordingly, the signals BT1 to BT7 sequentially become "1".

Therefore, keys C7 to C#3 of the melody key range UK
is scanned while the signals BT0 to BT3 are being generated, and the melody key range scanning timing signal UKT becomes "1" corresponding to this period (see FIG. 5c). Also, key C3 of the accompaniment keyboard range LK.
~C2 is scanned while signals BT4 and BT5 are being generated (specifically, up to the note timing of pitch name C, that is, the scanning timing of the lowest key C2 when signal BT5 is generated), and corresponds to this period. Then, the accompaniment key range scanning timing signal LKT becomes "1" (see FIG. 5c). After the scanning timing of the lowest key C2, that is, from the note timing of pitch name B when the signal BT5 is generated (see FIG. 5b) to the end of the signal BT7, no key corresponds to the period, and therefore the key data KTDM is not generated. .
After the signal BT7, the signal BT0 is generated again.
Signals BT0 to BT7 and UKT, LKT are output from the scan counter 49.

The sound generation assignment circuit 51 assigns the pressed keys in the melody key range UK to the melody sound generation channels Uch1 to Uch.
Functions assigned to any of 4 and accompaniment key range LK
It has a function of allocating each component tone of an accompaniment chord designated by a key press to one of the chord sounding channels Lch1 to Lch4, and a function of allocating an automatic bass tone to the bass sounding channel Pch.
In the sound generation allocation circuit 51, each sound generation channel
Uch1 to Uch4, Lch1 to Lch4, and Pch are processed in a time-sharing manner. Channel timing signals ch1 to ch8 and PchT indicating the time division timing of each sound generation channel are generated from a timing signal generation circuit 50.

The timing signal generation circuit 50 generates channel timing signals ch1 to ch8, PchT based on the system clock pulse φ as shown in FIG.
occurs in a time-division manner. Channel timing signals ch1 to ch4 are the melody sounding channel Uch1
- Channel timing signals ch5 to ch8 are generated corresponding to the time division timing of chord sounding channels Lch1 to Lch4, respectively, and channel timing signals PchT are generated corresponding to the time division timing of chord sounding channels Lch1 to Lch4. Occurs in accordance with the time division timing. The channel timing signals ch1 to ch4 are synthesized by the OR circuit 52 to form the melody channel timing signal UchT, and the signals ch5 to ch8 are synthesized by the OR circuit 53.
The synthesized signal is the chord channel timing signal.
LchT (see Figure 5a). As shown in FIG. 5a, one cycle of the clock pulse _φA generated from the timing signal generation circuit 50 is equivalent to 18 cycles (18 bit time) of the system clock pulse φ, and nine channel timing signals ch1 to ch
8. It is "1" during the 9-bit time of one round of PchT, and "0" during the 9-bit time of the second round. Similarly, the clock pulse φ _B generated by the timing signal generating circuit 50 has a phase opposite to that of the clock pulse φ _A , as shown in FIG. 5a.

An overview of the time relationships of various processes in one scanning cycle (from the timing of generation of signal BT0 to the timing of generation of signal BT7) is shown in the columns FC and SF in FIG. 5c. In the FC column, there is "Fingard Chord Mode" as an automatic performance mode.
An overview of the processing when is selected is shown.
The SF column shows an outline of processing when "single finger mode" is selected. In either finger chord mode FC or single finger mode SF, the scanning timing (signal
At the timing of BT0 to BT3), the melody key range indicated by the key data KTDM
UK press key melody pronunciation channel Uch1
~The process of allocating to Uch4 is executed (Fig. 5c)
(see 'UK quota').

In Finguard chord mode FC, the keys pressed in the accompaniment key range LK are directly used as chord constituent notes, so at the scanning timing of keys C3 to C2 in the accompaniment key range LK (timing of signals BT4 and BT5), the keys are The pressed keys of the accompaniment key range LK indicated by the data KTDM are used as the chord pronunciation channel.
Processing to allocate to Lch1 to Lch4 is performed (5th
(See “LK allocation” in Figure c). At this time, key data KTDM of keys C3 to C2 of the accompaniment key range LK is stored in the shift register 54. And the signal
At the timings of BT6 and BT7, the root note of the chord is detected based on the accompaniment key range key data stored in the shift register 54 (see "root note detection" in FIG. 5c). Signal BT for next scan cycle
At timing 0, a process is executed in which the bass note data formed using the detected root note is assigned to the bass note sound generation channel Pch (see "PK assignment" in FIG. 5c).

In single-finger mode SF, the accompaniment key range LK is used to specify the root note of the chord rather than the notes that make up the chord itself, so the scanning timing of the accompaniment key range LK (signal BT
4 and BT5), the pronunciation assignment process is not performed, and the process of detecting the highest pressed key in the accompaniment key range LK as the root note designated key is executed (see "LK highest note detection" in Figure 5c). ). At the timing of signal BT7, processing is executed to allocate the chord constituent tones automatically formed based on the pitch name of the detected highest pressed key, that is, the root note name, to the chord pronunciation channels Lch1 to Lch4 (see Fig. 5c). (See “SF chord assignments”). Signal BT for next scan cycle
At timing 0, finger code mode
Bass sound assignment processing (PK assignment) is executed in the same way as in the case of FC.

Circuits related to the pronunciation assignment process include a pronunciation assignment circuit 51, a truncate circuit 55, a key code memory 56, a comparison circuit 57, an octave code conversion circuit 58, and the like. The key code memory 56 includes a 9-stage circular shift register (not shown) corresponding to the number of channels, and each channel
The key codes KC* of the sounds assigned to Uch1 to Uch4, Lch1 to Lch4, and Pch are respectively stored and outputted in a time-divisional manner according to the system clock pulse φ. Key code output from scanning counter 49
Of KC, note code NC is input as is into key code memory 56, and octave code OC
is input to the key code memory 56 via the octave code conversion circuit 58. The octave code conversion circuit 58 is a circuit for forming an octave code OC' of chord constituent notes or an octave code OC'' of a bass note in the single finger mode SF.

The output key code KC of the scanning counter 49 is the key currently being scanned, that is, time division multiplexed key data.
Represents a key compatible with KTDM. The comparison circuit 57 compares the key codes assigned to each channel outputted from the key code memory 56 in a time-division manner.
KC* is compared with the key code KC given to the input side of the key code memory 56, and when the two match, a match signal EQ is output.

In the pronunciation assignment circuit 51, one key data
One allocation process is performed during one period (18 bit time) of the clock pulse _φA generated by KTDM. Therefore, in one allocation processing period, each channel timing goes around twice (see FIG. 5a). In the first 9-bit time of one allocation processing period, the clock pulse _φA becomes “1”,
In the latter 9-bit time, the clock pulse _φB becomes "1". In the pronunciation assignment circuit 51,
These clock pulses φ _A , φ _B and channel timing signals UchT, LchT, PchT (see Figure 5a)
The processing operation is controlled by.

First, the process of assigning keys to be pressed in the melody key range UK will be explained. The time division multiplexed key data KTDM output from the key scanning circuit 48 is input to AND circuits 59, 60, and 61, respectively. The other inputs of the AND circuit 59 are supplied with the melody key range scanning timing signal UKT (see FIG. 5c), and the other inputs of the AND circuits 60 and 61 are the accompaniment key range scanning timing signal LKT (5th (see figure c)
is added. Therefore, when the key data KTDM of the melody key range UK is being output, only the AND circuit 59 becomes operable, and the other AND circuits 6
0,61 becomes inoperable. As a result, the AND circuit 59 selectively outputs only the key data (indicated by KU) of the melody key range. The key data KU of the melody key range is generated by the sound generation assignment circuit 51
is input.

The sound generation allocation circuit 51 performs allocation processing to the melody sound generation channels Uch1 to Uch4 based on the key data KU of the melody key range.
The sound generation assignment circuit 51 stores the coincidence signal EQ output from the comparator circuit 57 when the clock pulse φ _A is "1" (first half assignment processing period), and stores this memory during the second half assignment processing period (when the clock pulse φ _B is "1"). It is held only for the 9-bit time when it becomes "1". Code EQM of stored match signal EQ
Indicated by EQM is "1" when the coincidence signal EQ is generated, and "0" when it is not generated (when there is no match). Furthermore, truncate channel designation signals TRU and TRL are inputted to the sound generation allocation circuit 51 from the truncate circuit 55 .
The truncate circuit 55 is a melody channel.
It detects the channel in which the key was released the earliest among Uch1 to Uch4, and generates the melody truncate channel designation signal TRU corresponding to the timing of that channel, and also generates the oldest key released channel in the chord channels Lch1 to Lch4. One channel in the state is detected and a chord truncate channel designation signal TRL is generated in accordance with the timing of that channel. In addition, a key-on memory 6 is provided in the sound generation assignment circuit 51.
2, each channel Uch1~Uch4,
Key-on signal KON indicating whether the key corresponding to the key code KC* assigned to Lch1 to Lch4 and Pch is currently pressed or released.
is output in a time-division manner. The key-on signal KON is “1” when the key is pressed, and “0” when the key is released.
It is.

In the sound generation assignment circuit 51, when the following logical condition is satisfied in relation to the key data KU of the melody key range (KU,, φ _B ,, TRU,
Generates load signal LD when UchT is all “1”.

LD＝KU・・φ _B・・TRU・UchT
...(4) The fact that the key data KU is "1" means that the key code KC given from the scanning counter 49 to the input side of the key code memory 56 in synchronization with the key data KU corresponds to the pressed key. It means something. Signal obtained by inverting the match memory signal EQM
The fact that EQM is "1" means that the coincidence signal EQ has not been generated, that is, the currently pressed key code KC corresponding to the above key data KU has not yet been assigned to any channel, and therefore the melody This means that it should be newly assigned to any of channels Uch1 to Uch4. The fact that the clock pulse φ _B is "1" indicates that it is the second half of the allocation processing period, that is, that the above signal is correct. key on signal
The fact that the inverted signal of KON is "1" indicates that it is the timing of the channel that is in the key release state. The fact that the melody truncate channel designation signal TRU is "1" means that it is the timing of the channel where the key was released the earliest, meaning that the old sound assignment for that channel may be deleted and a new assignment made. It means being a channel. The fact that the melody channel timing signal UchT is "1" indicates that it is the timing of the melody channel (the timing of the signals ch1 to ch4 in FIG. 5a).

When the condition of equation (4) above is satisfied, the load signal LD is generated only once corresponding to the channel timing of one of the melody channels. This load signal LD is applied to the load control input L of the key code memory 56. key code memory 5
6, the key code KC given from the scan counter 49 is taken and stored in place of the old key code KC* stored in the channel where the load signal LD was generated. Further, in the key-on memory 62, the key-on signal KON corresponding to the channel in which the load signal LD is generated is set to "1".

The key-on signal KON of the melody channel stored in the key-on memory 62 is reset to "0" when the following logical condition is satisfied.

・EQ・UchT・KON→KON reset...(5) The fact that the inverted signal of the key data KU is "1" means that the key corresponding to the key code KC given from the scanning counter 49 has been released. shows. The fact that the coincidence signal EQ and the signal UchT are "1" indicates that the same key code KC* as the released key code KC is assigned to the melody channel. Key-on signal KON is “1”
This indicates that the key assigned to the melody channel in which the coincidence signal EQ was generated had been pressed until just before. The key-on signal KON corresponding to the channel timing where the condition of equation (5) above is satisfied is reset to "0".

Next, the assignment process to the chord channels Lch1 to Lch4 in the fin guard chord mode FC will be explained. Finguard code mode
When FC is selected, the finger code mode signal FC becomes "1" and the single finger mode signal SF becomes "0". The finger code mode signal FC is applied to an AND circuit 60. Therefore, in the fine guard chord mode FC, keys C3 to C3 of the accompaniment key range are selected based on the accompaniment key range scanning timing signal LKT (see Fig. 5c).
The key data KTDM of C2 is selected by the AND circuit 60, and the chord key data is selected via the OR circuit 63.
It is supplied to the sound generation allocation circuit 51 as KL. still,
The output of the AND circuit 64 given to the other input of the OR circuit 63 is the single finger mode signal SF
It becomes "0" due to "0" of "0".

In the pronunciation assignment circuit 51, the chord key data KL
When the following logical conditions are satisfied in relation to (when KL, φ _B , TRL, and LchT are all "1"), a load signal LD is generated.

LD=KL・・φ _B・・TRL・LchT
...(6) The difference between the above equation (6) and the above equation (4) is that in relation to the chord key data KL, the chord truncate channel designation signal TRL and the chord channel timing signal LchT (Fig. 5a) (see) is used, and the meaning of the expression is almost the same as the above-mentioned expression (4). The processing when the load signal LD is generated (taking the key code KC into the key code memory 56 and storing the key-on signal KON) is the same as described above.

Further, the conditions for resetting the key-on signals KON of the chord channels Lch1 to Lch4 to "0" are as follows.

・EQ・LchT・KON→KON reset...(7) The meaning of this equation (7) is almost the same as the above-mentioned equation (6).

Next, the assignment of sound to the bass channel Pch in Finguard chord mode FC will be explained. The AND circuit 61 selects only the key data LKTDM of the accompaniment key area (keys C3 to C2) from the time division multiplexed key data KTDM based on the accompaniment key area scanning timing signal LKT (FIG. 5c). This accompaniment key range key data LKTDM
is taken into a 12-stage/1-bit shift register 54. The shift register 54 is shift-controlled by a clock pulse φ _A in synchronization with the key scanning timing, and the 12th stage Q
The output of 12 is returned to the first stage Q1 and circulated. The outputs of each stage of the shift register 54 are input in parallel to a root detecting ROM (abbreviation of read only memory, hereinafter the same) 65.

12 key data corresponding to keys C3 to C#2 of the accompaniment key range are stored in each stage of the shift register 54.
When LKTDM is incorporated, 12th stage Q1
2 outputs the key data of the highest key C3 in the accompaniment key range (“1” when the key C3 is pressed, “0” when it is not pressed), and from the 11th stage Q11 to Key B2 from 1st stage Q1
Key data of C#2 to C#2 is output. At this time, the AND circuit 61 selectively outputs the key data LKTDM of the lowest key C2, and the shift register 5
It is given to the first stage Q1 of 4. At the same time, the key data of the key C3 is given to the first stage Q1 of the shift register 54 from the 12th stage Q12. When the data of each stage is shifted to the next stage at the next shift timing, 1
Key data of key C2 or C3 (in short, key press data of pitch name C) is taken into stage Q1. In this way, each key C3 to C in the accompaniment keyboard area
The key data LKTDM of 2 is the note name C, B,
The data is converted into 12 note data corresponding to A...C#, and is held in circulation in the shift register 54. The note name of the note data output from the 12th stage Q12 of the shift register 54 is determined by the note counter section 4.
It corresponds to the note name of note code NC output from 9A. This is because the same note timing (see FIG. 5b) is repeated every 12 cycles of clock pulse φ _A. Therefore, the key data
The output of the 12th stage Q12, which is delayed from LKTDM by 12 cycles of the clock pulse _φA , matches the note timing of the key scan.

The root note detection ROM 65 uses the 12 note data given from each stage of the shift register 54 as address input, and determines whether a chord is formed from the combination of these note data values (“1” and “0”). When the chord is established, it outputs "1" at the timing when the chord is established, and when the chord is not established, it outputs "1" at the timing of the highest temperature. Of course, the note data corresponding to the pressed key is "1", and the note data corresponding to the key not pressed is "0". In the root note detection ROM 65, the note data output from the 12th stage Q12 of the shift register 54 is regarded as the 1st note 1, and the 1st to 11th stages are regarded as the minor 2nd degree ^B to the major 7th degree B. , it is determined whether the note data in the shift register 54 is "1" or "0" in a pitch relationship that satisfies a predetermined chord formation condition.
Since the note data in the shift register 54 is shifted sequentially, the root note detection ROM 65
By changing the note names in order, we will check whether a chord is formed or not.

The note data of keys C3 to C2 in the accompaniment keyboard area are finished being taken into the shift register 54 by the signal BT5.
(see FIG. 5C), and at the timing of the next signal BT6, the note data of all pressed keys in the accompaniment key area are reliably held in the shift register 54. Also, 1 where signal BT6 is generated
Shift register 5 at the note timing of 2
Since the note data of 12 in 4 goes through one cycle, the determination of whether or not a chord is established in the root note detection ROM 65 is completed reliably. Therefore, in the root note detection ROM 65, the signal
If the formation of a chord is not detected when BT6 is generated, when the next signal BT7 is generated, "1" is output corresponding to the note timing of the highest pressed key in the accompaniment key range, and this highest pressed key is set as the rhizome. I try to make it sound. Note data is stored in the shift register 54 in treble order (in the order of C, B, A#...C#)
Since the cycle occurs, the note timing of the highest pressed key is when "1" first arrives at the 12th stage Q12 of the shift register 54 at the timing of the signal BT7, and at that time, the root note detection ROM 65
It is configured to output "1" from . Of course, a chord is established at the timing of signal BT6, and ROM6 is generated at the note timing that indicates the root note of the chord.
If "1" is output from the signal BT7, the rhizoid selection process as described above is not performed at the timing of the signal BT7.

A signal “1” corresponding to the note timing of the root note output from the root note detection ROM 65 at the timing of the signal BT6 or BT7 is input to the AND circuit 66. The other inputs of the AND circuit 66 include the finger code mode signal FC and the signal BT6.
A signal BT6+BT7 which is OR-combined with BT7 is added. Therefore, Fingard code mode (FC
is “1”), the root note is detected at the timing of signal BT6 or BT7 (BT6+BT7 is “1”)
Data “1” corresponding to the note timing of the root note outputted from the ROM 65 passes through the AND circuit 66 and is input to the root note shift register 68 via the OR circuit 67. Note that the note data held in the shift register 54 is sent to the signal BT3 immediately before the accompaniment key range scan timing in the next scan cycle.
All are cleared by.

The root shift register 68 is a 12-stage/1-bit circular shift register, and is shift-controlled by a clock pulse _φA . In this root note shift register 68, a single signal "1" taken in at the note timing of the root note (or rhizoid note) is sequentially shifted and cyclically held. Therefore, "1" is output from the first stage Q1 of the root note shift register 68 at a note timing that is a semitone below the root note (major seventh), and "1" is output from the second stage Q2 at a note timing that is two semitones below the root note (major seventh). "1" is output at the note timing of the minor 7th (minor 7th), and from the 3rd stage to the 12th stage Q12, the major 6th to 1st (root) notes are output.
“1” is output at the note timing of . Therefore, each stage of the root tone shift register 68 corresponds to a number of tonal degrees. In addition, the root tone shift register 6
8 clears the "1" (old root note data) stored in the register 68 when "1" is applied from the OR circuit 67.

The outputs of each stage of the root note shift register 68 are input in parallel to a base note key data forming circuit 69 and an SF chord key data forming circuit 70. Bass pattern data BP generated from the rhythm pattern generation circuit 71 is decoded by the decoder 72 and input to the bass tone key data formation circuit 69. The bass pattern data BP is generated at the timing when the bass note should be produced.
The number of degrees of the bass note to be sounded (1 degree or 3 degrees)
This is a code signal that indicates the degree, etc., pitch relative to the root note). The base note key data forming circuit 69 selects the output of the stage corresponding to the base tone degree decoded by the decoder 72 from among the outputs of each stage of the root note shift register 68 and supplies it to the AND circuit 73 . The other input of the AND circuit 73 is a signal.
BTO has been added. Root shift register 6
The root note data is taken into 8 at the timing of signal BT6 or BT7, so the next signal
At the timing of BT0, data "1" reliably makes one round in the root note shift register 68. Therefore, by enabling the AND circuit 73 at the timing of the signal BT0, correct data can be taken out from the bass note key data forming circuit 69. The output of the AND circuit 73 is input to the sound generation assignment circuit 51 as base tone key data KP.
This base tone key data KP becomes "1" at the note timing of the note name corresponding to the number of tones specified by the base pattern data BP.

When the base sound key data KP becomes “1”,
The note code NC output from the note counter section 49A indicates the note name of the bass note specified by the bass note key data KP. At this time, the octave code conversion circuit 58 outputs an octave code OC'' for the bass tone corresponding to the timing of the bass tone channel.The AND circuit 74 is supplied with the signal BT0 and the bass tone channel timing signal PchT ( (see FIG. 5a) is input to the AND circuit 7 at the bass tone channel timing when the signal BT0 for generating the bass tone key data KP is generated.
The output of 4 becomes "1". Octave conversion circuit 5
8, when the output of the AND circuit 74 is "1",
The value of the octave code OC is converted into an octave code OC'' indicating the octave range for the bass tone and output. Therefore, the key code KC input to the key code memory 56 and comparison circuit 57 is the note code NC and the octave code OC''. OC'', and represents the bass tone corresponding to the bass tone key data KP.

In the pronunciation assignment circuit 51, the base tone key data
A load signal LD is generated when the following logical condition regarding KP is satisfied.

LD=KP・_φB・PchT...(8) In other words, when the bass sound key data KP becomes " ₁ ", the channel timing for the bass sound (PchT is 1), the load signal LD is generated. Based on this load signal LD, a key code of a bass tone consisting of a note code NC and an octave code OC'' is loaded into the key code memory 56, and a key-on signal KON is stored in the key-on memory 62.

Next, processing in single finger mode SF will be explained. When the single finger mode is selected, the finger code mode signal FC is "0" and the single finger mode signal SF is "1". Therefore, the AND circuit 60 becomes inoperable due to "0" of the signal FC,
Key data actually pressed in the accompaniment key range
KTDM is not used as chord key data KL. In addition, the AND circuit 6
6 also becomes inoperable, and the output of the root note detection ROM 65 is also not used.

The key data LKTDM of the accompaniment key range selected by the AND circuit 61 is input to the highest note detection circuit 75. The highest note detection circuit 75 detects the highest pressed key in the accompaniment key range as the root specified key in single finger mode SF. In the time-division multiplexed accompaniment key range key data LKTDM, data for each key C3 to C2 appears in treble order at the timing of signals BT4 and BT5, so the first time "1" appears is in the accompaniment key range. This corresponds to the scanning timing of the most pressed key. Therefore, the highest note detection circuit 75 preferentially selects the first arriving "1" of the time-division multiplexed key data LKTDM and inputs it to the AND circuit 76 as the root note designation key data SFRT. Further, the highest note detection circuit 75 stores that the root note specifying key data SFRT has been selected as a priority, and blocks subsequent key data LKTDM (on the lower note side than the highest note) based on this memory. This memory is cleared at the timing of signal BT3 in the next scanning cycle.

The other input of the AND circuit 76 is connected to the signal BT4.
A signal BT4+BT5 obtained by ORing BT5 and a single finger mode signal SF are added, and the output is sent to the root tone shift register 6 via an OR circuit 67.
8 is input. Therefore, when in single finger mode (SF is "1"), the root note specification key data
“1” is taken into the root shift register 68 at the timing when SFRT becomes “1”. As described above, a single "1" is circulated in the root tone shift register 68, and "1" is output in order from each stage corresponding to the frequency (7), (7b)...(2b), (1). be done. The timing at which "1" is output from each stage corresponding to each frequency (7) to (1) is determined by the root note designation data SFRT. For example, the root note specification data SFRT is note name C.
If it becomes “1” at the note timing of , it is a major 7.
From the first stage Q1 of the shift register 68 corresponding to degree (7), “1” is generated at the note timing of note name B.
is output.

The SF chord key data forming circuit 70 uses a minor chord selection signal min and a seventh chord selection signal 7th.
The output of a predetermined stage of the root tone shift register 68 is selected according to the contents of the root note shift register 68 and is applied to the AND circuit 64. The chord selection signals min and 7th are signals for selecting and specifying the type of chord in single finger mode; when both signals min and 7th are "0", it is a major chord, and when the signal min is "1", it is a minor chord. When the chord signal 7th is "1", it indicates a seventh chord. These chord selection signals min and 7th may be generated based on selection operations using dedicated switches min-SW and 7th-SW as in the example shown in Fig. 1, or may be generated based on selection operations using a keyboard. It may also be configured to occur. In the SF chord key data forming circuit 70, in the case of a major chord (both min and 7th are "0"), the 12th stage and 8th stage of the root tone shift register 68 correspond to the 1st, major 3rd, and perfect 5th.
The outputs of the 5th and 5th stages are selected, multiplexed, and supplied to the AND circuit 64. Further, in the case of a minor chord (min is "1"), the output of the 9th stage corresponding to the minor 3rd is selected instead of the 8th stage corresponding to the major 3rd. Also, in the case of a seventh chord (7th is "1"), instead of the 5th stage corresponding to the perfect 5th, the 2nd stage corresponds to the minor 7th.
Select the output of the stage.

The signal BT7 and the single finger mode signal SF are input to other inputs of the AND circuit 64. Therefore, the multiplexed key data of each chord component tone for the single finger mode output from the SF chord key data forming circuit 70 is based on the timing of the signal BT7 in the single finger mode (SF is "1") (see FIG. 5c), it passes through an AND circuit 64 and is supplied to the sound generation assignment circuit 51 as chord key data KL via an OR circuit 63.

Chord key data in pronunciation assignment circuit 51
The allocation conditions regarding KL are as shown in equation (6) above. By the way, in the case of single finger mode, the chord key data KL is the signal as described above.
Since it is generated at the timing of BT7, the content of the octave code OC output from the octave counter section 49B at that time is a value that does not correspond to the actual keyboard range. Therefore, the octave code conversion circuit 58 converts this octave code OC into an octave code OC' indicating a predetermined octave range for chords. That is, single finger mode signal SF
and signal BT7 are input to the AND circuit 77, and when the output of the AND circuit 77 is "1" (that is, when the conditions of the AND circuit 64 are satisfied and the chord key data KL for single finger mode is generated) ) The octave code conversion circuit 58 converts the octave code OC into a chord octave code.
Convert to OC′ and output. Therefore, when the assignment condition is satisfied for the key data KL generated at a certain note timing and the load signal LD is generated, the note code NC indicating the note name of the key data KL and the chord octave code OC' are The key code KC consisting of the combination is stored in the key code memory 56.
be taken into account. Note that Equation (7) above does not apply to resetting the key-on signal KON of the chord channel in single finger mode, and when there are no keys pressed in the accompaniment key range, the key-on signal of the chord channel is reset. KON will be reset.

The base tone key data formation and its pronunciation assignment processing in the single finger mode SF are the same as in the case of the finger chord mode FC described above.

As described above, each channel Uch1 to Uch4, Lch1 to Lch4,
The key code KC* assigned to Pch is memorized,
In addition, the key-on memory 62 stores a key-on signal indicating key press or key release assigned to each channel.
KON will be remembered. The key code KC* and key-on signal KON of each of these channels are stored in memory 5.
6 and 62 in a time-division manner, and are supplied to a melody tone forming circuit 78, a chord tone forming circuit 79, and a bass tone forming circuit 80, respectively.

The melody musical tone forming circuit 78 has four musical tone forming series corresponding to the melody sounding channels Uch1 to Uch4, and each channel Uch1 to Uch4.
Channel timing signal ch1 corresponding to Uch4
- Each channel according to ch4 (see Figure 5 a)
Key codes assigned to Uch1 to Uch4
KC* and key-on signal KON for each channel Uch1
- Distribute and latch the musical tone formation series corresponding to Uch4. In each musical tone forming series Uch1 to Uch4, based on the distributed key code KC* and key-on signal KON, a musical tone signal of a pitch corresponding to the key code KC* is generated while the key-on signal KON is "1". , output with a melody tone added.

The musical tone forming circuit 79 for chords has four musical tone forming series corresponding to the chord sounding channels Lch1 to Lch4, and uses the key code KC* and key-on signal KON assigned to each channel Lch1 to Lch4 to these channels. According to the channel timing signals ch5 to ch8 (FIG. 5a) corresponding to the tone forming series Lch1 to Lch4, the tone forming sequences are distributed and latched, respectively. Each musical tone forming series Lch1 to Lch4 of the musical tone forming circuit 79 for chords forms a musical tone signal with a pitch corresponding to the distributed key code KC* while the key-on signal KON is "1", and creates a tone for chords. Grant. And each series Lch1~Lch
The musical tone signals formed in step 4 are simultaneously controlled to open and close in accordance with the chord generation timing pattern pulse CT given from the rhythm pattern generation circuit 71, and are output.

In the bass tone forming circuit 80, the key code assigned to the bass tone generation channel Pch is
KC* and key-on signal KON are connected to channel timing signal PchT (5th
Latch according to figure a) and the latched key code
Based on KC* and the key-on signal KON, a musical tone signal of the bass tone is generated. Sound channel for bass
Since the Pch key-on signal KON becomes "1" in a time-sharing manner at the timing when the bass tone should be generated (the timing at which the bass pattern data BP is generated), the bass musical tone forming circuit 80 outputs the bass tone at the timing according to the bass pattern. A sound signal is generated.

The musical tone signals outputted from each musical tone forming circuit 78, 79, and 80 and the rhythmic tone signal outputted from the rhythm sound source circuit 82 are applied to a sound system 81 and generated. Note that the gates 83 and 84 provided between the chord tone forming circuit 79 and the bass tone forming circuit 80 and the sound system 81 are as follows:
It becomes non-conductive when five keys are pressed to control the start/stop of the rhythm pattern, and is always in a conductive state during normal performance.

Next, the key press number detection circuit 12A will be explained.
The key data LKTDM of the accompaniment key range selected by the AND circuit 61 is applied to the count input of a counter 85, and the counter 85 counts the number of keys being pressed simultaneously in the accompaniment key range. The output of the counter 85 is applied to the A input of the comparison circuit 86. A code X indicating a predetermined number of pressed keys (for example, 5) for instructing start-stop control of the rhythm pattern is added to the B input of the comparison circuit 86. When A≧B, that is, when the number of keys pressed simultaneously in the accompaniment key area is equal to or greater than the predetermined number (5), the output of the comparison circuit 86 becomes “1”, and the start/stop control circuit 13A outputs the 5 key press detection signal 5K. is input.

The counting operation of the counter 85 is controlled in accordance with the clock pulse _φA synchronized with the key scanning timing. That is, when the key data LKTDM applied to the count input is "1", the clock pulse _φA is counted. For example, keys B2, A
When #2, A2, G#2, and G2 are pressed, the key data LKTDM is continuously "1" during five consecutive time slots corresponding to keys B2 to G2.
However, since five clock pulses φ _A are generated during that time, the counter 85 is counted up by five. The count contents of counter 85 are cleared at the beginning of each scan cycle by signal BT0.

Any key-on detection circuit 87 is an AND circuit 61
This circuit detects whether any key is pressed in the accompaniment key area based on the key data LKTDM given from LKTDM, and outputs an any key-on signal AKO if any key is pressed. The any-key-on detection circuit 87 includes a primary memory and a secondary memory (not shown), and when the key data LKTDM becomes "1" at a timing corresponding to any of the keys C3 to C2 in the accompaniment key range. "1" is stored in the primary memory at the end of the scan cycle (for example, at the timing of the signal BT7), and the storage in the primary memory is transferred to the secondary memory, and at the beginning of the next scan cycle (at the timing of the signal BT0). Clear the memory in the primary memory (at the timing of ). Then, the contents stored in the secondary memory are output as an any key-on signal AKO. Therefore, if any key is pressed in the accompaniment key range, the any key-on signal AKO will remain at "1" continuously.

Any key-on signal AKO and 5 keystroke detection signal 5
Start-stop control circuit 13A to which K is input
has exactly the same structure as the start/stop control circuit 13 shown in FIG. 2 or 3, and functions in the same manner. Therefore, the start-stop control circuit 1
When the configuration of the circuit 13 shown in Fig. 2 is adopted as 3A, when five or more keys are pressed simultaneously in the accompaniment key range, the 5 key press detection signal 5K becomes "1" and the rhythm start signal RS is reset to "0". be done. In this way, generation of the rhythm patterns BP, CT, and PT in the rhythm pattern generation circuit 71 can be stopped by simultaneously pressing five or more keys in the accompaniment key area. Start-stop control circuit 1
When the configuration of the circuit 13 shown in FIG. 3 is adopted as 3A, the state of the rhythm start signal RS is reversed based on the 5-key press detection signal 5K generated by pressing 5 or more keys simultaneously in the accompaniment key area ( “0”
to "1" or from "1" to "0"), both the start and stop of the rhythm pattern can be controlled by key press operations.

5 keystroke detection signal 5 output from comparison circuit 86
K is also input to latch circuit 88. A signal BT7 is applied to the control input L of the latch circuit 88.
The counter 85 counts the number of pressed keys using the signal BT4.
and BT5 timing, so
Counting has already been completed at the timing of signal BT7, and a correct comparison result has been output from comparison circuit 86. Therefore, when five or more keys are pressed at the same time in the accompaniment key area, the five key press detection signal 5K output from the comparison circuit 86 at the timing of the signal BT7 is "1", and the latch circuit 88 outputs "1". 1” is latched. The output of latch circuit 88 is inverted by inverter 89 and applied to control inputs of gates 83 and 84, respectively. Gates 83 and 84 are conductive when the output of inverter 89 is "1", that is, when the output of latch circuit 88 is "0". When five or more keys are pressed simultaneously in the accompaniment key area, "1" is latched in the latch circuit 88, the output of the inverter 89 becomes "0", and the gate 8
3 and 84 become non-conductive. As a result, the chord tone forming circuit 79 and the bass tone forming circuit 80
The musical tone signals outputted from the two are blocked by gates 83 and 84, respectively, and the generation of chords and bass notes is prohibited. At this time, the chords and bass tones generated from the chord tone forming circuit 79 and the bass tone forming circuit 80 are formed based on five or more key depression operations in the accompaniment key area. The key pressing operations of five or more keys in the accompaniment key range are not for the purpose of playing chords or bass notes, but for the purpose of controlling the start-stop of the rhythm pattern.
The musical tone signals output from the musical tone forming circuits 79 and 80 based on these five or more key depression operations are meaningless. Gates 83 and 84 are provided to inhibit such meaningless musical tone signals.

Although gates corresponding to the gates 83 and 84 for inhibiting sound production as shown in FIG. 4 are not particularly shown in the embodiment shown in FIG. 1, it is possible to provide similar gates for inhibiting sound production. Not even.

In each of the embodiments described above, a part of the keyboard area of the single-level keyboard is used as an accompaniment keyboard area, but the accompaniment keyboard area may be the entire keyboard (for example, the lower keyboard of a two-level keyboard). Further, in the above embodiment, the target keyboard for detecting the number of keys pressed simultaneously for start-stop control of rhythm pattern generation operation is the accompaniment key range.
The entire keyboard, including the melody keyboard area (or keyboard) or the melody keyboard area (or keyboard) and the accompaniment keyboard area (or keyboard), can also be used as the target keyboard for simultaneous key depression detection. Furthermore, in the above embodiments, chords, bass sounds, and rhythm sounds are given as examples of automatic accompaniment sounds generated based on rhythm patterns, but it is not necessary to generate all of these sounds as automatic accompaniment sounds, and any one sound can be used. It may also be a sound other than a chord, a bass sound, or a rhythm sound (for example, an arpeggio sound).

As explained above, according to the present invention, it is possible to control the stop and start of the rhythm pattern generation operation using the keyboard, so a foot switch is not required. This eliminates the need to provide a foot switch on the expression pedal, reducing manufacturing costs. In addition, since it can be controlled manually rather than using a difficult foot switch, even beginners can easily control the start and stop of the rhythm while playing the keyboard (for example, while continuing to play the melody in the melody key range). become able to. What's more, unlike operating the rhythm start/stop switch on the front panel, all you have to do is press the keys at the same time with your hands placed on the keyboard, so your hand movements are not wasted, and you can This does not interfere with keyboard performance (for example, continuation of melody performance). Therefore, the present invention is also useful for desk-top electronic musical instruments that cannot be equipped with a foot switch.

Furthermore, since any key can be operated as long as it is at least a predetermined number of keys, there is no problem of erroneous operation, and the generation of automatic accompaniment sounds is prohibited while operating at least a predetermined number of keys. Therefore, there is no problem of mispronunciation, and any key can be used for musical tone performance (automatic accompaniment tone performance), which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the overall configuration of an electronic musical instrument showing one embodiment of the present invention in an analog electronic musical instrument.
FIG. 2 is a circuit diagram showing a detailed embodiment of the key press number detection circuit and start-stop control circuit shown in FIG. 1, and FIG. 3 is a circuit diagram showing another embodiment of the start-stop control circuit shown in FIG. , FIG. 4 is a block diagram of the overall configuration of an electronic musical instrument showing one embodiment of the present invention in a digital electronic musical instrument, and FIG. 5 is a timing chart showing the time relationship of various operations in FIG. The time scale is shown on a larger scale than in FIG. 1B, and the time scale in FIG. 12, 12A...key press number detection circuit, 13, 13
A...Start/stop control circuit, 14, 71...
...Rhythm pattern generation circuit, START/STOP...
...Rhythm start/stop switch, SYNC...
Synchro start switch.

Claims (1)

[Scope of Claims] 1. In an automatic accompaniment device for an electronic musical instrument that controls the production of automatic accompaniment sounds such as chords, bass sounds, rhythm sounds, etc. based on the output of a rhythm pattern generation circuit, a start/stop control circuit that starts or stops the operation of the rhythm pattern generation circuit when the detection circuit detects a predetermined number of keys or more; An automatic accompaniment device for an electronic musical instrument, comprising: a sound generation inhibiting means for inhibiting the sound generation of the automatic accompaniment sound while a key press is detected.