JPH0131638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a musical tone signal generating device used in electronic musical instruments, etc., and particularly to a musical tone signal generating device that generates a musical tone signal whose timbre changes depending on pitch or range. It is related to.

(Prior art and its problems) In general, the tone of the sound of a natural instrument changes depending on its pitch (or range), and as typified by the sound of a piano, the lower the pitch, the higher the harmonics. There are many wave components, and as the pitch increases, the harmonic components of high frequencies decrease.

It is desirable for a musical tone signal generating device for an electronic musical instrument to be able to generate sounds as close to those of a natural musical instrument as possible.

In this way, one method of generating musical sound signals close to the sounds of natural instruments has been to
It has been proposed to store different tone waveforms for each tone in a waveform memory, and to select and read out a tone waveform corresponding to the pitch (range) of the pressed key. However, according to such a method, the capacity of the waveform memory becomes enormous, the structure becomes large, and it is also very disadvantageous in terms of cost.

(Summary of the Invention) An object of the present invention is to provide a musical tone signal generating device that can generate musical tone signals that are very close to the sounds of natural instruments without causing any disadvantages in terms of structure or cost. .

That is, in this invention, the pitch of the musical tone signal to be generated is specified by the pitch specifying means, and the first waveform having a predetermined harmonic component at the specified pitch is generated by the first waveform generation signal. At the same time, the second waveform generating means generates a second waveform signal having more harmonic components of a higher frequency than the first waveform signal at the specified pitch, and the synthesizing means generates a second waveform signal having more harmonic components of a higher frequency than the first waveform signal. The second waveform signal is synthesized, and the pitch specified above (or the range to which the pitch belongs) is generated by a parameter signal generating means equipped with a memory.
generates a parameter signal corresponding to the pitch specified by the pitch specifying means or the synthesis ratio of the first and second waveform signals in the synthesizing means by the action of the control means using the parameter signal. Control is performed so that as the range of pitches increases, the synthesis rate of the second waveform signal decreases and the synthesis rate of the first waveform signal increases.

Through such control, it is possible to obtain a musical tone in which high frequency harmonic components decrease as the pitch of the generated musical tone or the range to which the pitch belongs rises.

(Example) In the following description, in order to generate higher quality musical tone signals,
An example in which the present invention is applied to an electronic musical instrument disclosed in No. 48412 (Japanese Unexamined Patent Publication No. 134418/1983) in which the timbre of a musical tone signal is changed over time like the sound of a natural instrument will be described.

In FIG. 1, the output side of a keyboard circuit 1 is connected to the input side of a frequency information memory 2. As shown in FIG. The output side of the frequency information memory 2 is connected to the input side of an accumulator 3, and a clock pulse φ is input to an accumulation command terminal of the accumulator 3. The output side of the accumulator 3 is connected to the input sides of waveform memories 4, 5, 6, and the output sides of the waveform memories 4, 5, 6 are connected to the first input terminals of the multipliers 7, 8, 9, respectively. It is connected. The output side of each multiplier 7-9 is connected to the input side of adder 10, respectively.

The output side of the adder 10 is connected to a first input terminal of a multiplier 16, and a second input terminal of the multiplier 16 receives a key-on signal KON output from the keyboard circuit 1 when a key is pressed. The envelope waveform EV output from the envelope waveform generator 15 is input. The output side of the multiplier 16 is connected to a sound system 17 consisting of a digital-to-analog converter, an amplifier, a speaker, and the like.

The parameter signal generator 30 also includes a key tone balance parameter table 31 whose address input side is connected to the output side of the keyboard circuit 1, and a counter 3 whose address input terminal is connected to the output side of the keyboard circuit 1, and a counter 3 whose count input terminal receives a clock pulse φ.
2, a parameter time change memory 33 whose address input side is connected to the output side of the counter 32, a first input terminal A to the output side of the key tone balance parameter table 31, and a first input terminal A to the output side of the parameter time change memory 33. an adder 34 to which the second input terminal B is connected, and an adder 3 to which the input terminal is connected.
4, and a parameter calculation device 35 whose output terminals A, B, and C are connected to second input terminals of multipliers 7, 8, and 9, respectively.

Here, the keyboard circuit 1 has a plurality of key switches provided respectively corresponding to a plurality of keys as a pitch specifying means of the present invention for specifying the pitch of a musical tone to be generated. When a key is pressed, a key switch corresponding to the key is operated to output a logic value "1" to an output line corresponding to the key.
Keyboard circuit 1 has a built-in single note priority circuit,
The single note priority circuit has a function of determining only one note to be produced when two or more keys are pressed at the same time. Further, the keyboard circuit 1 has a function of outputting a key-on signal KON indicating that a certain key is pressed. Further, the frequency information memory 2 stores frequency information F (constant) having a value corresponding to the pitch of each key.

Note that the key-on signal KON output from the keyboard circuit 1 when a key is pressed is sent to the counter 3 on the one hand.
The signal is input to the reset terminal R of No. 2, and the envelope waveform generator 15 is input to the other end. In this case, the envelope waveform EV generated by the envelope waveform generator 15 has a waveform shape, for example, as shown in FIG. It can be set to .

By the way, in this embodiment, the waveform memory 4 stores a waveform as shown in FIG. 3A, which includes many harmonic components.
The waveform amplitude value of W1 is stored, the waveform memory 5 stores the waveform amplitude value of the waveform W2 as shown in FIG. 3B, which has relatively few harmonic components, and the waveform memory 6 stores the harmonic It is assumed that the waveform amplitude value of the waveform W3 shown in FIG. 3C, which has very few components, is stored. Note that these waveform memories 4
6 correspond to the first and second waveform generating means of the present invention, together with the frequency information memory 2 and the accumulator 3, respectively. Regarding each waveform memory 4, 5, and 6, the first waveform generating means corresponds to the waveform memory 5, and the second waveform generating means having more harmonic components than the first waveform generating means corresponds to the waveform memory 5. At the same time, the first waveform generating means corresponds to the waveform memory 6 and the second waveform generating means corresponds to the waveform memory 5. Changes in these correspondence relationships are caused by considerations regarding the setting of the key range of the electronic musical instrument and temporal changes in musical sound waveforms, which will be described later.

In addition, key tone balance parameter table 3
1 corresponds to the parameter signal generating means of the present invention, and is composed of a read-only memory, etc., and each address stores, for example, keys A ₀ to C ₈ (88 keys) as shown in FIG. Each value of a parameter (constant) K _p (a value that gradually changes from negative to positive as the pitch increases) corresponding to the pitch of each key is stored. In addition, the parameter time change memory 33 stores, for example, a parameter P(t) as shown in FIG.
is memorized.

On the other hand, the parameter calculation device 35 constitutes the control means of the present invention, and the output of the adder 34
The following (a) corresponds to the value of P′(t) (=K _p +P(t)).
,
Perform the calculation as shown in (b), and output the parameter signals a(t), b(t), and c from the output terminals A, B, and C, respectively.
(t).

(b) When P′(t)≧0; a(t)=0, b(t)=1−c(t), c(t)=P′(t) (b) P′(t) When <0; a(t)=|P′(t)|, b(t)=1−a(t), c(t)=0 Multipliers 7, 8, and 9 are the parameter calculation device 3
5 constitutes the control means of the present invention, and each waveform amplitude value from each waveform memory 4, 5, 6
W1, W2, and W3 are multiplied by parameter signals a(t), b(t), and c(t) from the parameter calculation device 35, respectively, and output. The adder 10 receives the multiplication results W1・a(t), W2・b(t), W3・c(t).
By adding and outputting to the multiplier 16, each waveform amplitude value W1, from each waveform memory 4, 5, 6 is
It combines W2 and W3 and supplies it to the multiplier 16, and corresponds to the combining means of the present invention.

The effects of this embodiment having the above configuration will be described next.

When a certain key is pressed, frequency information F corresponding to the pitch of that key (the pitch of the musical sound to be generated) is output from the frequency information memory 2, and this frequency information F is output by the accumulator 3 to the clock pulse φ. It is accumulated sequentially at the timing of , and the accumulated value qF (q=1, 2...)
are sequentially input to the waveform memories 4, 5, and 6 as read address signals. The waveform memories 4, 5, and 6 receive this read address signal and convert the waveform amplitude values stored in the addresses specified by the read address signal into waveform signals W1, W2, and W3.
Read out sequentially as . As a result, the waveform memories 4, 5, and 6 obtain waveform signals W1, W2, and W3 that correspond to the pitches of the pressed keys and have different waveforms. The waveform signal W1 read out from the waveform memory 4 in this manner is input to the multiplier 7, where it is multiplied by the parameter signal a(t) output from the parameter signal generator 30. Therefore, the waveform signal output from the multiplier 7 is W1·a(t). Similarly, the waveform signals read from the waveform memories 5 and 6
W2 and W3 are multiplied by the parameter signals b(t) and c(t) in multipliers 8 and 9 to produce a waveform signal W2・b.
(t), W3・c(t). Each of these waveform signals W1・a(t), W2・b(t), W3・c(t)
is input to the adder 10 and added, so the musical tone signal output from the adder 10 is [W1・a(t)
+W2・b(t)+W3・c(t)].

On the other hand, in the parameter signal generator 30,
Logic value 1 is applied to the output line corresponding to the pressed key of keyboard circuit 1.
Therefore, the key tone balance parameter table 31 outputs a parameter K _p having a value corresponding to the pitch of the pressed key. Now, if we consider the case where key _A2 is pressed, the pressed key has pitch _A2 , so the value of K _p is "-0.5" as is clear from FIG. 4.
The output value K _p =-0.5 of this key tone balance parameter table 31 is input to the first input terminal A of the adder 34 .

Further, at the same time as the key is pressed, the key-on signal KON is output from the keyboard circuit 1 and is input to the reset terminal R of the counter 32, so that the counter 32 starts counting the clock pulses φ from the initial value. The count value of the counter 32 is input as a read address signal to the parameter time change memory 33, and the parameter time change memory 33 stores the parameter P that changes as shown in FIG. 5 at each address.
(t) are output sequentially. This time-varying parameter P(t) is input to the second input terminal B of the adder 34, so that the adder 34 outputs the
Output P'(t)=K _p +P(t). (As mentioned above, since key A ₂ is pressed here, K _p = -
It is 0.5. ) In this way, the adder 34 adds the parameter (information) K _p regarding the pitch of the pressed key and the parameter (information) P(t) regarding the key pressing time.

Next, the changes over time of each parameter signal a(t), b(t), c(t) output by the parameter signal generator 30 will be explained according to the change over time of the parameter P(t) shown in FIG. .

At time t ₀ (see FIG. 5), P(t ₀ )=-0.25, so P'(t)=K _p +P(t)=-0.75. Therefore, since P'(t)<0, the parameter calculation device 35 performs the calculation in (b) above, and a(t ₀ )=0.75, b
(t ₀ )=0.25 and c(t ₀ )=0.00 are output, respectively.
These parameter signals a(t ₀ ), b(t ₀ ), c(t ₀ )
are multiplied by the waveform signals W1, W2, and W3 output from the waveform memories 4, 5, and 6, respectively, and sent to the adder 1.
It is added as 0. Therefore, the musical tone signal output from the adder 10 is (0.75W1+0.25W2). This musical tone signal is composed of a waveform signal W1 with many harmonics [Fig. 3A] and a waveform signal W2 with relatively few harmonics [Fig. 3B] in a ratio of 3:1. This results in many musical sound waveforms.

At time t ₁ , P(t ₁ )=0.5, so P'(t ₁ )=K _p
+P(t ₁ )=0. Therefore, the parameter calculation device 35 performs the calculation in (a) above, and a(t ₁ )=0, b
Outputs (t ₁ )=1 and c(t ₁ )=0. Therefore, in this case, the musical tone signal outputted by the adder 10 is the same as the waveform signal W2 with less harmonics.

Next, consider the case where key _A4 is pressed. In this case, as is clear from FIG. 4, K _p =0.25.

At time t ₀ , P(t ₀ )=−0.25, so P'(t ₀
)
=K _p +P(t ₀ )=0. Therefore, the parameter calculation device 35 performs the calculation in (a) above, and a(t ₀ )=
0, b(t ₀ )=1, c(t ₀ )=0. Therefore, in this case, the musical tone signal outputted by the adder 10 becomes a waveform signal W2 with relatively few harmonics.

At time t ₁ , P(t)=0.5, so P'(t)=
It becomes 0.75. Therefore, the parameter calculation device 35 performs the calculation in (a) above, and a(t)=0, b(t)=
0.25 and c(t)=0.75, respectively. Therefore, the musical tone signal output by the adder 10 is (0.25W2
+0.75W3), and the waveform signals W2 and W3 are 1:3.
It becomes a composite product with the ratio of

In this way, the musical tone signal [W1・a(t)+W2・b(t)+W3・c(t)] output from the adder 10
is multiplied by the envelope waveform EV output from the envelope waveform generator 15 in the multiplier 16, subjected to envelope control, and given an appropriate volume, and then produced by the sound system 17.

Up to this point, we have explained the case where keys A ₂ and A ₄ are pressed, but when other keys are pressed, parameters (constants) related to the pitch of the pressed key are obtained from the key tone balance parameter table 31 in exactly the same way. K _p
is read out, a parameter P(t) related to the key press time is read out from the parameter time change memory 33, and is output from each waveform memory 4, 5, 6 based on both parameters K _p and P(t). Parameter signals a(t), b(t), and c(t) for weighting the waveform signals W1, W2, and W3 are generated from the parameter calculation device 35. Therefore, like a natural musical instrument, the waveform shape (timbre) changes depending on the pitch of the pressed key.
Furthermore, it is possible to generate a musical tone whose waveform shape (timbre) constantly changes from the time the musical tone is generated to the end.

In the above explanation, three waveform memories are provided,
Although an example has been shown in which three series of waveform signals W1, W2, and W3 are synthesized to form a musical tone signal, the number of waveform signals to be synthesized can be arbitrarily selected. Furthermore, it goes without saying that the waveform shape of each waveform signal to be synthesized can be arbitrarily selected.

Further, in the above embodiment, the key tone balance parameter table 31 has been described as storing a parameter K _p having a different value for each pitch, but the present invention is not limited to this. For example, Parameters with different values for each range
It is also possible to memorize K _p .

(Effects of the Invention) As is clear from the above description, according to the present invention, the first harmonic component having a predetermined harmonic component is The synthesis ratio of the waveform signal and the second waveform signal that has more harmonic components of higher frequencies than the first waveform signal is determined such that as the pitch or range increases, the second waveform signal decreases and the first waveform signal
The musical tone signal is formed by controlling the waveform signal to increase, so it does not increase the size of the structure or increase the cost, and the high pitch increases as the pitch or range increases. It is possible to generate high-quality musical tones that are very close to the sounds of natural instruments with reduced wave components.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing one embodiment of the present invention, Fig. 2 is a waveform diagram showing an example of an envelope waveform, and Fig. 3 A, B, and C show an example of the waveforms stored in each waveform memory. FIG. 4 is a waveform diagram showing an example of the parameter K _p stored in the key timbre balance parameter table, and FIG. 5 is a waveform diagram showing an example of the parameter P(t) stored in the parameter time change memory. It is a diagram. 1...Keyboard circuit, 2...Frequency information memory, 3
... Accumulator, 4, 5, 6 ... Waveform memory, 7,
8,9,16... Multiplier, 10,34... Adder, 17... Sound system, 30... Parameter signal generator, 31... Key tone balance parameter table, 32... Counter, 33... Parameter Time change memory, 35...Parameter calculation device.

Claims (1)

[Scope of Claims] 1. Pitch specifying means for specifying the pitch of a musical tone signal to be generated; and a first waveform signal having a pitch specified by the pitch specifying means and having a predetermined harmonic component. a first waveform generating means for generating a second waveform signal having a pitch specified by the pitch specifying means and having many harmonic components of a higher frequency than the first waveform signal; 2 waveform generating means, a synthesizing means for synthesizing the first and second waveform signals to generate a musical tone signal, and a parameter signal for controlling the synthesis ratio of the first and second waveform signals, respectively. a parameter signal generating means having a memory stored corresponding to a pitch or each pitch range, and generating a parameter signal corresponding to the pitch specified by the pitch specifying means or the pitch range to which the pitch belongs; Based on the parameter signal generated from the signal generating means, the synthesis ratio of the first and second waveform signals in the synthesizing means is adjusted to a pitch specified by the pitch specifying means or an increase in the range to which the pitch belongs. Accordingly, a musical tone signal generating apparatus comprising a control means for controlling the synthesis rate of the second waveform signal to decrease and the synthesis rate of the first waveform signal to increase.