JPS6132678B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to improvements in automatic rhythm performance devices. As shown in FIG. 1, the conventional automatic rhythm performance device oscillates a basic tempo clock pulse TCP, divides this pulse TCP as appropriate in a frequency dividing circuit 1, and forms pulses with various periods. These pulses are appropriately combined in the rhythm pattern forming circuit 2 and
Ten types of rhythm pattern signals (pulse trains) are formed, and these rhythm pattern signals are sent to the rhythm selection circuit 3 according to the selection made by the rhythm selection switch 4.
The types of percussion instrument sound sources in the sound source section 5 are driven to oscillate in accordance with the selected and combined outputs. Since this sound source section 5 is an analog circuit equipped with individual oscillators corresponding to various percussion instrument sounds such as cymbals and maracas, a pattern generator section 6 consisting of a frequency dividing circuit 1, a rhythm pattern format circuit 2, and a rhythm selection circuit 3
Although the use of IC has improved cost, reliability, implementation, etc., the sound source section 5 has not been made into IC. This invention aims to achieve complete digitization of the entire automatic rhythm performance device by digitizing the sound source section of the automatic rhythm performance device, and to improve cost, reliability, and implementation by making it easier to integrate it into an IC. It is something to do. This invention converts a rhythm pattern signal (pulse) corresponding to each percussion instrument sound output from a pattern generator into a time-division signal, converts the time-division signal into a digital signal corresponding to the frequency of the percussion instrument sound, and converts the time-division signal into a digital signal corresponding to the frequency of the percussion instrument sound. The waveform amplitude of the percussion instrument sound is sequentially read out from the waveform storage device according to the signal. Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, a pattern generator section 6 is a conventionally well-known circuit, and a tempo clock pulse TCP oscillated from an oscillator 7 is applied to a plurality of stages of frequency dividing circuits 1. The frequency dividing circuit 1 is a multi-bit binary counter, and when performing a rhythm performance, the start/stop switch 8 is turned on to enable the frequency dividing circuit 1 and count the pulse TCP. The rhythm pattern forming circuit 2 forms a predetermined rhythm pattern signal according to the output of the frequency dividing circuit 1,
It is configured so that several dozen types of rhythm pattern signals are output as respective pulse trains. The rhythm pattern forming circuit 2 is constructed using a diode matrix, read-only memory, or the like. The rhythm selection circuit 3 selects one or several rhythms in a predetermined combination from all the output pulse trains of the rhythm pattern forming circuit 2 in response to a rhythm selection operation on a rhythm selection switch 4 that selects various rhythms such as waltz and tango. A pattern signal (pulse train) is selected, and these selected rhythm pattern signals are guided to an output line 9 corresponding to a predetermined percussion instrument sound in the selected rhythm. For example, rhythm selection circuit 3
The 11 output lines in output line 9 correspond to 11 types of percussion instrument sounds as shown in Table 1 below. A predetermined rhythm pattern signal (pulse train) is guided to each of the output lines 9 according to the selected rhythm. Table 1 is
One of the waveforms and frequencies that determine the tone quality of each percussion instrument sound.
This is an example of only noise damping sound N.
Or only the sine wave damping sound S, or the mixture of the noise damping sound N and the sine wave damping sound S.
+S etc.

[Table] The signal on line 9 is applied to a channel separator 10 and is time-divided for each type of percussion instrument. The time-divided signal is applied to the encoder 11, where it is converted into 4-bit code signals C ₁ , C ₂ , C ₃ , and C ₄ .
Multiplexed. Further, a noise-attenuated sound signal is guided to a noise sound source 13 via an OR circuit 12. Code signals C ₁ to _{C 4} corresponding to the time-division multiplexed percussion instrument sounds are held in a hold circuit 14 and used for waveform reading and envelope application. FIG. 3 shows a detailed example of the channel separator 10, the encoder 11, and the hold circuit 14. The channel separator 10 is sequentially operated at the timing of the clock pulse φ by the output "1" of each stage of the 10-stage shift register 15. enabled
It has ten AND circuits 16-1 to 16-10, and signals on line 9 corresponding to each percussion instrument sound are separately applied to each AND circuit 16-1 to 16-10. The outputs of all stages of the shift register 15 are added to the OR circuit 17, and when all the output stages become "0", "1" is read into the first stage, so that a single signal "1" shift register 1
Circulate within 5. AND circuits 16-1 to 16-1
0 can be operated time-divisionally at the speed of the clock pulse φ, so the AND circuits 16-1 to 16-10
In this step, rhythm pattern signals corresponding to each percussion instrument sound are selected in a time-division manner. Note that the clock pulse φ that determines the time division rate is much faster than the pulse time width of the rhythm pattern signal. In the example in the figure, the snare drum rim shot SDH sound is the sound of the snare drum noise SDN and high bongo HB played at the same time.
The rhythm pattern signal of the snare drum rim shot SDH is guided through diodes 18 and 19 to AND circuits 16-4 and 16-6 corresponding to the snare drum noise system SDN and high bongo HB. FIG. 4 shows the channel time slots to which each percussion instrument sound is assigned as a result of time division in the channel separator 10. As shown in the time slot shown in FIG. 4, each AND circuit 16-1 to 16-
At this time, only the AND circuit (any one of 16-1 to 16-10) corresponding to the percussion instrument sound in which the pulse of the rhythm pattern signal is generated outputs signal 1. The encoder 11 has, for example, 4 bits corresponding to each bit.
It has three OR circuits 20, 21, 22, and 23, and encodes the signal "1" output from each AND circuit 16-1 to 16-10 into a 4-bit code signal _C1 to _C4 . For example, in the case of cymbal CY ₁ , the output of the AND circuit 16-1 is applied only to the OR circuit 20, resulting in a code signal of "1000" where bit _C1 is "1" and bits _C2 to _C4 are "0". .
Also, in the case of maracas MA, AND circuit 16-3
The output of is added to OR circuits 20 and 21, and the bit
The code is "1100" where C ₁ and C ₂ are "1" and bits C ₃ and C ₄ are "0". In Figure 3,
This indicates that the output lines of the AND circuits 16-1 to 16-10, which intersect the input lines of the OR circuits 20 to 23 with circles, are input to the OR circuit. Since the outputs of the AND circuits 16-1 to 16-10 are time-division multiplexed as described above, the encoder 11 outputs the code signals _C1 to _C4 of each percussion instrument sound in a time-division multiplexed manner. The hold circuit 14 holds each bit _C1 to _C4 of the code.
10-stage shift registers 24 corresponding to the
It has an OR circuit 25 and an AND circuit 26. The number of stages of the shift register 24 is the same as the number of time division channels. Output code of encoder 11
C ₁ to C ₄ are stored in each shift register 24 via each OR circuit 25, and the output of the final stage is stored in each shift register 24 again via each AND circuit 26 and OR circuit 25. Therefore, when a rhythm pattern signal is output for a certain percussion instrument sound on line 9, the encoder 11 outputs that percussion instrument sound at the time slot of the percussion instrument sound (see FIG. 4) only when a pulse of the rhythm pattern signal occurs. Code signals C ₁ to C ₄ representing
The code signals C ₁ to _{C 4} are stored in each shift register 24 in the hold circuit 14, and are output from the shift register 24 at the next time slot (same channel time) regarding the same percussion instrument sound. The code signals C ₁ to _{C 4} are stored in the register 24 again in the hold circuit 14 in a time-division manner. When the sound generation ends in the relevant time slot (channel) and the decay end signal DF is generated (becomes "1"), the output of the inverter 27 becomes "0", the AND circuit 26 becomes inoperable, and memory retention is canceled. be done. Code signals C _{1 to 1} corresponding to each percussion instrument sound held in the hold circuit 14 and time-division multiplexed output
_C4 joins frequency rate memory 28, attach rate memory 29, and decay rate memory 30 (FIG. 2) and serves as an address input for each memory 28-30. The frequency rate memory 28 stores numerical values corresponding to the frequencies of each percussion instrument sound (see Table 1 above) as binary information, and the numerical information F read from the frequency rate memory 28 is stored in the counter 3.
1, and the output of the counter 31 is stored in the waveform memory 3.
Used as address input for 2. Assuming that the speed of the time division clock pulse φ is 1 μs, the number of times the numerical information F is accumulated by the counter 31 is once every 10×10 ⁻⁶ (seconds) since the number of channels is 10. Furthermore, if one period waveform is stored in the waveform memory 32 using 64 sample points, then the frequency f
The numerical information F of a percussion instrument sound (Hz) is given by the formula: F=f×64×10 ⁻⁵ . However, percussion sounds such as cymbals, maracas, snare drum noise, etc. that only have noise damping sounds do not have a specific frequency.
Since the waveform memory 32 is not used, when the code signals C ₁ to _{C 4} of the noise attenuated sounds are input into the frequency rate memory 28, a value of 0 is read out, and the waveform counter 31 is not driven. The waveform counter 31 includes a 10-stage shift register 31a shifted by a clock φ and an adder 3.
1b, and integrates and counts the value of the numerical information F of each channel supplied from the frequency rate memory 28 in a time-division manner. The amplitude of each waveform sample point is read from the waveform memory 32 using the count output of the waveform counter 31 as an address. The waveform memory 32 stores, for example, a one-cycle waveform of a sine wave. The amplitude envelope such as attack and decay of the sine wave signal read out from the waveform memory 32 is controlled by the envelope signal read out from the envelope memory 33. The envelope memory 33 stores envelope signals having characteristics of attack A and decay D as shown in FIG. 5 in positive and negative symmetry (+E, -E). The attack time and decay time in the envelope are determined by the magnitude of the values read from attack rate memory 29 and decay rate memory 30. Since each percussion instrument sound has a different attack time and decay time, numerical values corresponding to each percussion instrument sound are stored in memories 29 and 30, respectively. At the beginning of the sound, the attach memory 29 becomes operational due to the signal "1" from the inverter 34. The attack memory 29 reads out a numerical value corresponding to the attack time of the percussion instrument sound in accordance with the percussion instrument sound codes C ₁ to C ₄ added in a time-division manner from the hold circuit 14 . This numerical value is sequentially integrated and counted in an envelope counter 35, and the output of the envelope counter 35 becomes an address for reading out the envelope memory 33. The envelope counter 35 is the same as the frequency counter 31.
It has an adder and a shift register similarly to
Time division sharing of each channel is now possible.
Since the count value of the envelope counter 35 increases at a speed proportional to the size of the value read from the attack memory 29, the time of the envelope A of the attack portion read from the envelope memory 33 according to the size of the value. is controlled. For example, the larger the value, the shorter the attack time and the steeper the rise of the attack envelope. When the calculated value of the envelope counter 35 reaches the final address of the attack envelope (for example, "1111"), the condition of the AND circuit 36 is satisfied and a signal "1" is outputted via the OR circuit 37. Therefore, the output of the inverter 34 becomes "0" and the attach memory 29 becomes inoperable. At this time, the decay rate memory 30 becomes operational, and a numerical value corresponding to the decay time of the percussion instrument sound is read out from the memory 30 in accordance with the percussion instrument sound codes C ₁ to _{C 4} added in a time-divisional manner from the hold circuit 14 . The envelope counter 35 sequentially adds the numerical value read out from the decay rate memory 30 to the final address of the attack envelope, thereby further advancing the address in the envelope memory 33. Since the decay envelope is stored next to the attack in the envelope memory 33, the envelope waveform D of the decay portion is read out subsequent to the attack A. As with the attack, the decay time is controlled by the magnitude of the numerical value read from the decay rate memory 30. Therefore, by storing appropriate numerical values for each percussion instrument sound in the attack rate memory 29 and decay rate memory 30, a desirable envelope signal (+E, -
E) can be obtained. When the count value of the envelope counter 35 reaches the final address of the decay envelope (for example, "111111"), the condition of the AND circuit 38 is satisfied,
The output of the circuit 38 becomes "1" and the decay end signal DF is generated. As a result, the memory of the channel in the hold circuit 14 is cleared, and the waveform counter 31 and envelope counter 3 are also cleared.
The contents of the channel in step 5 are cleared, and the sounding of the channel ends. The waveform memory 32 and the envelope memory 33 are stored in, for example, Japanese Patent Application No. 106945/1983
A memory such as that described in the specification of "Semiconductor Waveform Memory Device" (No. 66121) can be used. That is, it has a voltage divider circuit that obtains a voltage corresponding to the amplitude voltage at each address, and an electronic switch that is opened in response to address input, and is configured so that the amplitude voltage of a desired address can be extracted from the voltage divider circuit. be. Envelope waveforms +E, -E read out symmetrically from the envelope memory 33
(see FIG. 5) are supplied as positive and negative power supplies to the voltage dividing circuit in the waveform memory 32. Therefore, as the envelope waveform changes in amplitude over time, the voltage dividing circuit power supply of the waveform memory 32 changes, and the amplitude value of each waveform sample point taken out from the voltage dividing circuit changes. In this way, a sine waveform that has been envelope-controlled in advance is read out from the waveform memory 32 as shown in FIG. Of course, it is not limited to this,
An envelope can be added to a waveform signal using a multiplier or a coefficient multiplier. Rhythm pattern signals related to each percussion instrument sound of the nozzle attenuation sound system that are time-divided by the channel separator 10 are multiplexed via the OR circuit 12, and are applied to the gate circuit 39 of the noise sound source 13 to control opening of the gate. A pulse with a random period is inputted to the gate circuit 39 from the noise pulse generator 40 . The details of the noise sound source 13 are shown in FIG. 7. The noise pulse generator 40 includes a 9-bit shift register 41, an exclusive OR circuit 42, and a NOR circuit 43.
and an OR circuit 44. shift register 41
is shifted by the clock pulse φ, but pulses are generated at completely random periods from the final stage as shown in FIG. 8C. Random pulses from the shift register 41 are led out to the waveform memory 32 only when the gate circuit 39 is opened by the output "1" from the OR circuit 12. For example, suppose that the rhythm pattern pulse of cymbal CY ₁ appears on line 9 (FIG. 2) as shown in FIG. 8a. Since the cymbal CY ₁ is assigned to the first channel in the channel separator 10, the output of the OR circuit 12 for only the time of the first channel to which the cymbal CY ₁ is assigned is shown in FIG. 8b. In this case, the gate circuit 39 is opened at the timing shown in FIG. 8b. Therefore, the random pulse shown in FIG. 8c is selected when the gate is opened, and the output of the gate circuit 39 is
It will look like Figure d. The output of the gate circuit 39 is sent to the address decoder 32a of the waveform memory 32 as the most significant bit (weight 3).
2) via the OR circuit 45. Also,
The output of the OR circuit 12 which controlled the gate circuit 39 (time-division multiplexed rhythm pattern pulse of noise attenuated sound, see FIG. 8b) is sent to the OR circuit 4.
6 to the input of the decoder 32a of the bit one bit below the most significant bit (weight 16). A noise waveform is read from the waveform memory 32 based on the outputs of the OR circuits 45 and 46 (that is, the address of the upper two bits). During the channel time of the noise sound in which the rhythm pattern pulse is generated, the output of the OR circuit 46 is always "1" (see FIG. 8b), and when a random pulse is output from the gate circuit 39 during that channel time. The output of the OR circuit 45 becomes “1” (the 8th
(see figure d). Therefore, there are only two addresses from which to read the noise waveform. That is, when the output of the OR circuit 45 is "1", the address input code of the waveform memory 32 is "110000", which is address 48. Further, when the output of the OR circuit 45 is "0", it is "010000", which is address 16. Therefore, the noise waveform is 16 times the sine waveform stored in the waveform memory 32.
It is formed only by the address and the sample point amplitude at address 48. As shown in FIG. 9, the amplitudes at addresses 16 and 48 are approximately the maximum positive and negative amplitudes of the sine wave. Therefore, in the case of FIG. 8d, when the time slots t ₁ , t ₂ , t ₄ , t ₅ , and t ₆ are allocated by time division, the address of the waveform memory 32 is 16, so a positive amplitude voltage is generated. At time slots _t3 and _t7 , the address is 48, so a negative amplitude voltage is read out. If the noise waveform read out by the pulse of FIG. 8d is roughly drawn, ignoring the time interruption caused by the time division clock, it will be approximately as shown in FIG. 8e. In reality, there is a large difference in the time scale between the rhythm pattern pulse (FIG. 8a) and the time division clock (FIG. 8b). (for example,
Rhythm pattern pulses are a few Hz, while time division clocks are a few hundred KHz to 1 MHz). Of course, in the case of noise attenuated sound, the code C ₁ ~
_C4 is held in the hold circuit 14, appropriate numerical values are read out from the attach rate memory 29 and decay rate memory 30, and envelope waveforms +E and -E are read out from the envelope memory 33. Therefore, an envelope is added to the noise waveform output from the waveform memory 32. The waveform read from the waveform memory 32 is a time-division multiplexed sine waveform and a noise waveform, and is applied to a clock removal filter 47 to remove high frequency components due to the time-division clock. After that, audio lamp 48, speaker 4
It is pronounced after 9. Note that in the case of a percussion instrument sound that is a mixture of noise and a sine wave (snare drum noise SDD), the waveform memory 32 cannot be used to read out both the sine wave and the noise waveform at the same time. Therefore, as shown in FIG.
It is connected to the SDN line, and the noise system and sine wave system are processed on separate channels. As explained above, according to the present invention, it is possible to completely digitize the sound source section of an automatic rhythm performance device.

[Brief explanation of the drawing]

Fig. 1 is a block diagram for explaining a conventional automatic rhythm performance device, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a detailed diagram of the channel separator, encoder, and hold circuit shown in Fig. 2. Figure 4 is a graph showing the time slots of time-division channels for various percussion sounds assigned in the channel separator, Figure 5 is a graph showing an example of attack and decay envelope shapes, and Figure 6 is envelope control. Graph showing an example of a waveform signal of a percussion instrument sound, No. 7
The figure is a block diagram showing details of a digital noise sound source, Figure 8 is a timing chart explaining the generation of noise waveforms in relation to Figure 7, and Figure 9 is a sine wave one-cycle waveform amplitude stored in the waveform memory. It is a graph showing the relationship between and address. 6...Pattern generator section, 10...Channel separator, 11...Encoder, 13...
...Noise sound source, 14...Hold circuit, 28...
Frequency rate memory, 29... Attack rate memory, 30... Decay rate memory, 31...
Waveform counter, 32... Waveform memory, 33... Envelope memory, 35... Envelope counter.

Claims (1)

[Scope of Claims] 1. An automatic rhythm performance device that generates a rhythm pattern signal indicating the sound generation timing of each percussion instrument sound in response to a selected rhythm, and generates each percussion instrument sound in response to the rhythm pattern signal. , an allocation means for allocating signals corresponding to each percussion instrument sound of the rhythm pattern signal to time division channels set corresponding to each percussion instrument sound, and waveform data corresponding to each percussion instrument sound at a plurality of sample point amplitude values. a waveform memory means for storing each address at each address; and an address signal for reading out the waveform data stored in the waveform memory means in response to a signal corresponding to each percussion instrument sound assigned by the assigning means. a waveform data reading means for reading out waveform data corresponding to each percussion instrument sound from the waveform memory in a time-division manner by forming each divided channel from the waveform memory according to the address signal; An automatic rhythm performance device comprising a musical sound generating means for automatically generating each percussion instrument sound in response to waveform data obtained by performing a percussion instrument. 2. The automatic rhythm performance device according to claim 1, wherein the assignment means includes means for converting a signal corresponding to each percussion instrument sound of the rhythm pattern signal into code information corresponding to the percussion instrument sound.