JPH0631963B2 - Electronic musical instrument - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an electronic musical instrument that generates a musical tone with a vibrato effect or a repeat effect by appropriately modulating the pitch or amplitude or tone color of a generated musical tone. Is.

[Prior art]

Conventionally, when forming a musical tone corresponding to the pitch of a pressed key on a performance keyboard, a stored program type arithmetic unit, a so-called microcomputer, is used to detect the pressed state of the key and a modulation effect such as a vibrato effect. Also detects the setting state of the modulation effect controller,
By giving this detection result to the tone forming circuit (tone generator), a tone corresponding to the pitch of the pressed key is formed in this tone forming circuit, and the tone pitch, amplitude or tone color of this tone is manipulated for modulation effect. There is an electronic musical instrument which is modulated by a low-frequency modulation waveform signal set by a child to generate a musical sound to which a vibrato effect or a repeat effect is added.

However, in this conventional electronic musical instrument, the tone forming circuit controls the frequency and amplitude of the modulation waveform signal generated from the modulation low-frequency oscillator by wire logic according to the setting state of the modulation effect operator, and The tone signal corresponding to the pitch of the pressed key is modulated by the controlled modulated waveform signal. For this reason, the configuration becomes complicated, and when it is necessary to change the content of the modulation effect, the circuit board itself has to be replaced, which is not flexible.

[Object and Structure of Invention]

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to be flexible in changing the content of a modulation effect, and to generate a musical sound to which a modulation effect such as a vibrato effect is added with a simple configuration. The purpose is to provide electronic musical instruments.

To this end, the present invention provides a performance keyboard, a modulation waveform designating means for designating the frequency and depth of a modulation waveform, a tone forming means, and a modulation waveform memory storing a plurality of amplitude values of continuous sampling points of the modulation waveform. A modulation waveform data storage means for temporarily storing the modulation waveform data, a program memory in which a key processing program and a modulation waveform processing program for calculating the modulation waveform data are stored in advance, and one arithmetic processing unit of a stored program system. Then, (A) according to the key processing program, (1) a process of outputting key information corresponding to a key pressed based on the pressed state of the playing keyboard to the tone forming means, and (B) the According to the modulation waveform processing program (1) sampling points from the modulation waveform memory at a speed according to the frequency of the modulation waveform designated by the modulation waveform designating means Processing for sequentially reading the width value, and (2) controlling the level of the read sample point amplitude value according to the depth of the modulation waveform designated by the modulation waveform designating means to obtain each sample point of the modulation waveform. The process of sequentially calculating the modulated waveform data indicating (3) and the process of (3) sequentially storing the modulated waveform data in the modulated waveform data storage means are performed in a time division manner.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of an electronic musical instrument according to the present invention. In the figure, reference numeral 10 denotes various calculations and data transfer described later such as detection of a key pressing state of a playing keyboard and calculation of modulation waveform data for modulation effect according to a program previously stored in a ROM (read only memory) 11. An arithmetic processing unit (CPU) for executing processing, the CPU
In addition to the ROM 11, the address bus and data bus 10 include a RAM (random access memory) 12 for temporarily storing operation data, and a keyboard circuit 13 having a key switch corresponding to each key of a performance keyboard (not shown). A control switch circuit 14 having an operator for setting a modulation effect such as a vibrato effect is connected in parallel.

In this case, as shown in FIG. 2, the control switch circuit 14 has a modulation depth (DEPT) of the vibrato effect.
H), modulation speed (SPEED), and delay time (DELAY) data for delay vibrato effect, and operators 140 to 142 for vibrato effect, and modulation depth of repeat effect (a kind of amplitude modulation effect) ( DEPT
H) and operating speeds 143 and 144 for setting respective data of modulation speed (SPEED) and one of a sine wave, a trapezoidal wave, a square wave, and a sawtooth wave with a downward slope as a modulation waveform of the repeat effect. A modulated waveform selection operator 145 and a tone color selection operator group 146 including a plurality of operators for selecting tone colors of musical tones such as violin and flute are provided.

On the other hand, the data bus of the CPU 10 includes a level data output register 15 for temporarily storing the amplitude modulation waveform data LMD for the repeat effect calculated by the CPU 10, and the CPU 1
A pitch data output register 16 for temporarily storing the pitch modulation waveform data PMD for the vibrato effect calculated by 0
And are connected. In this case, the amplitude modulation waveform data LMD sent to the data bus of the CPU 10 is the decode signal DEC ₁ obtained by the decoder 17 decoding the device address data of the level data output register 15 sent to the address bus in synchronization with this data LMD. Is written in the level data output register 15. Similarly, the pitch modulation waveform data PMD sent to the data bus of the CPU 10 is synchronized with this data PMD by the decode signal DEC ₂ obtained by decoding the device address data of the pitch data output register 16 sent to the address bus by the decoder 18. Then, it is written in the pitch data output register 16.

Further, the data bus of the CPU 10 is provided with n time-division tone generation channels CH _{1 to} C via an interface circuit 19.
A shift register 20 having a storage position corresponding to each of H _n is connected, and the key code KC of the key assigned to each pronunciation channel based on the detection of the pressed key and the pronunciation assignment process and the key code KC that has been released from the time when the key is pressed. A key-on signal KON for sounding control that keeps a predetermined level until key operation is transferred from the data bus of the CPU 10 via the interface circuit 19 to generate these key codes K.
A set of data consisting of C and a key-on signal KON is stored in each storage location. It should be noted that each of the _n time-division sound generation channels CH _{1 to} CH _n is defined by one cycle time of the clock pulse φ generated from the clock oscillator 21, and all sound generation channels CH are generated in n cycle time of the clock pulse φ. _{1 to} CH _n are configured to make _one cycle. Along with this, the shift register 20 also has n storage locations corresponding to the pronunciation channels CH _{1 to} CH _n as described above, and each storage location has a tone channel CH _k (k corresponding to the storage location. = 1 to n), the key code KC and the key-on signal K of the key assigned
ON is stored, and the stored contents are sequentially shifted to the output side storage position each time the clock pulse φ is generated, thereby synchronizing with the time division timing (channel timing) of each time division tone generation channel CH _{1 to} CH _n. The output side storage positions are then sequentially output. In this case, the assignment of the pressed keys to the pronunciation channels is performed by the pronunciation assignment process of the CPU 10. When the CPU 10 determines the pronunciation channels for producing the tones corresponding to the pressed keys by the pronunciation assignment process. Sends the channel number CH _k (k = 1 to n) indicating the assigned channel number to the data bus together with the key code KC corresponding to the pressed key and the key-on signal KON. Then, the key code KC and the key-on signal KON
Is transferred to the input side storage position of the shift register 20 in synchronization with the channel time corresponding to the channel number CH _k by the channel synchronization function of the interface circuit 19 and stored in the shift register 20.

Therefore, the interface circuit 19 having such a channel synchronization function is constructed as shown in FIG. 3, for example. That is, the register 19 for storing the channel number CH _k , the key code KC and the key-on signal KON
0, a channel counter 191 which counts the clock pulse φ and repeatedly outputs a channel number signal CH _i (i = 1 to n), a channel number CH _k among the contents stored in the register 190 and a channel number signal output from the channel counter 191. A comparator 192 for comparing with CH _i ,
CH _k = CH _i, and the match signal EQ is output from the comparator 192.
A selector for selecting the key code KC and the key-on signal KON from the contents stored in the register 190 when the (“1” signal) is output and supplying the selected key code KC and the key-on signal KON to the shift register 20 of FIG.
193, and further decodes the device address data of the register 190 sent from the address bus of the CPU 10 and sends the channel number CH _k and the key code K sent from the data bus by the decode signal DEC _3.
It has a decoder 194 for storing the C and key-on signal KON in the register 190.

Therefore, the register 19 is assigned with the pronunciation assignment of the new pressed key.
When the channel number CH _k , the key code KC, and the key-on signal KON are newly stored in 0, the channel number CH _k and the channel number signal CH among the stored contents are stored.
_i becomes compared with each other, and when both match, the key code KC and the key-on signal KON among the contents stored in the register 190 are synchronized with the coincidence signal EQ in synchronization with the channel timing of the channel indicated by the channel number CH _k. Is selectively output from the selector 193, transferred to the input side storage position of the shift register 20, and stored therein. At the timing when the coincidence signal EQ of "1" is not generated, the selector 193 selects the key code KC and the key-on signal KON output from the output side storage position of the shift register 20 and stores them in the input side storage position of the shift register 20. Return and re-memorize. When the pressed key is released, the channel number CH _k and the key code KC are set to “0”.
Key-on signal KON is transferred to and stored in the register 190. Therefore, the channel number CH at this time
At the storage position of the shift register 20 corresponding to _k , the key code KC and the key-on signal KON of "0" are stored, and the generation of the musical sound is stopped. As a result, the shift register 20 always stores the key code KC corresponding to the current pressed key and the key-on signal KON of "1" for instructing the tone generation of the tone corresponding to the key code KC. .

On the other hand, the data bus of the CPU 10 is connected with the interface circuit 22 and the shift register 23, which have exactly the same configurations as the interface circuit 19 and the shift register 20. The interface circuit 22 and the shift register 23 are provided to control the tone color and amplitude envelope of a musical tone for each sounding channel according to the tone range (pitch) of the pressed key, for example. The tone color parameter data TCP _k corresponding to the tone color selected and set by the child group 146 and corresponding to the tone range of the pressed key assigned to each tone generation channel, and the envelope data ENVD _k for forming the envelope waveform signal are each tone generation channel. Separately, when the data bus of the CPU 10 is transmitted together with the channel number CH _k , these data TCP _k , E
NVD _k is based on the channel synchronization function of the interface circuit 22 and each tone generation channel CH of the shift register 23.
It is stored in a storage location corresponding to ₁ to CH _n.

The envelope data ENVD _k and the tone color parameter data TCP _k are preliminarily stored in the ROM 11 in correspondence with various tone colors and ranges, and are assigned to the tone colors selected by the tone color selection operator group 146 and the respective pronunciation channels. Predetermined parameter data is read out in correspondence with the tone range of the pressed key.

The key code KC of the key code KC and the key-on signal KON output from the shift register 20 in synchronization with the channel timing corresponding to each sounding channel.
Is supplied to the phase data generating circuit 24 including a frequency number memory 240, an adder 241, and an accumulator 242. Further, the key-on signal KON is supplied to an envelope waveform generator (ENV · G) 25 that generates an amplitude envelope waveform signal ENV _k for each sounding channel. Moreover, the envelope data envd _k of envelope data envd _k and tone color parameter data TCP _k is outputted in synchronization with the shift register 23 to the channel timing corresponding to each sound channel is supplied to the envelope waveform generator 25, the latter The tone color parameter data TCP _k is supplied to the tone generator 26.

The phase data generation circuit 24 generates phase data qF (q = 1, 2, 3, ...) Which designates the phase of the tone wave sample point amplitude value to be generated in the tone generator 26, and has a frequency number. When the key code KC corresponding to the depressed key is given to the memory 240 as an address signal, the frequency number F corresponding to the key code KC is generated from the frequency number memory 240. Then, the frequency number F is given to the accumulator 242 via the adder 241 and repeatedly accumulated for each sounding channel, so that the accumulated value q of the repetition period corresponding to the pitch of the pressed key.
F is formed and the accumulated value qF is output as phase data. In this case, the pitch modulation waveform data PMD output from the pitch data output register 16 is supplied to one input of the adder 241, and the frequency number F output from the frequency number memory 240 corresponds to this pitch modulation waveform data PMD. Are modulated and added to the accumulator 242. By this,
The accumulator 242 executes accumulation based on the added value "F + PMD" of the frequency number F and the pitch modulation waveform data PMD. The accumulation operation in the accumulator 242 is executed for each channel corresponding to each time-sharing sounding channel.

On the other hand, the envelope waveform generator 25 generates an amplitude envelope waveform signal ENV _k for setting the amplitude of each tone channel of each tone generation channel.
Envelope data ENVD _{k for} each channel is given by giving the key-on signal KON for each channel.
Envelope waveform signal ENV for each channel based on
Start generating _k .

The tone generator 26 sequentially forms the amplitude values of each sample point of the tone waveform in time-division for each sounding channel according to the phase data q "F + PMD" output from the phase data generation circuit 24, and forms the sample point amplitude thus formed. The value is output as the instantaneous amplitude value Gk (t) of the tone signal. in this case,
The tone color (waveform shape) of the musical tone waveform formed in the tone generator 26 is set for each tone generation channel by tone color parameter data TCP _k provided from the shift register 23.

The instantaneous amplitude value Gk (t) of the tone signal of each tone generation channel output from the tone generator 26 is supplied to the multiplier 27, and the envelope waveform signal for each tone generation channel output from the envelope waveform generator 25 is supplied here. Amplitude setting is done by multiplying by ENV _k ,
Further, the amplitude is modulated by being multiplied by the amplitude modulation waveform data LMD output from the level data output register 15. The tone signal Gk (t) for each sounding channel subjected to this amplitude modulation is converted into an analog tone signal in the sound system 28 and is then sounded as a tone.

By the way, the ROM 11 stores the pitch modulation waveform data PMD.
And _five waveform tables WT ₁ to WT ₅ are provided as shown in the memory map of FIG. 4 in order to generate the amplitude modulation waveform data LMD by arithmetic processing, and the waveform table WT ₁ is provided with a desired vibrato effect. The amplitude value of the sampling point of the pitch modulation waveform is stored. Further, the sine wave for Repito effect in the waveform table WT ₂ ~WT _5, a trapezoidal wave, a square wave, sample point amplitude values for each amplitude modulated waveform of the sawtooth wave is stored. Similarly, in order to generate the pitch modulation waveform data PMD and the amplitude modulation waveform data LMD by the arithmetic processing, the RAM 12 uses the memory area thereof to modulate the pitch modulation wave phase data register REG ₁ and speed data register REG _2. , Delay data register REG ₃ , depth data register RE
G ₄ is provided, and a modulation wave phase data register REG ₅ and speed data register RE for amplitude modulation are provided.
G ₆ , a depth data register REG ₇ , and a waveform selection data register REG ₈ are provided.

Next, the operation of the electronic musical instrument configured as described above is shown in FIG.
Description will be made based on the flow chart shown in FIG.

First, when the power is turned on, the CPU 10 repeatedly executes the key scanning process to the amplitude modulation waveform data transfer process shown in steps 1000 to 1009 of FIG.
In the 0 key scanning process, the operation state of the key switch in the keyboard circuit 13 is detected by sequential scanning. As a result of this sequential scanning, when it is detected that the operation state of the key switch has changed, the step 1001 is followed by the step 100.
Then, the process proceeds to the process of No. 2 and the tone assignment process is executed. That is, if the cause of the change in the operating state of the key switch is due to the pressing operation of a new key, this pressing key is assigned to any of the blank pronunciation channels which have not yet been assigned pronunciation among the n pronunciation channels. with channel number CH _k indicating allocation channel sends a key-on signal KON of the key code KC and corresponding to the pressing keys "1" to the data bus. At the same time, the device address data of the register 190 in the interface circuit 19 is sent out from the address bus. By this,
Key code KC and key-on signal KO of the new pressed key
N is a shift register 2 via the interface circuit 19.
It is stored in the storage location corresponding to the channel number CH _k at 0. However, if the cause of the change in the operating state of the key switch is due to the key release operation, the CPU 10 stops the sounding together with the channel number indicating the channel to which the release key is assigned and the key code KC of the release key. The key-on signal KON of "0" is sent to the data bus, and at the same time, the device address data of the register 190 in the interface circuit 19 is sent from the address bus. Then, the key code K of this release key
The key-on signal KON of C and “0” is given to the shift register 20 via the interface circuit 19. As a result, the key-on signal KON of "1" is changed to the key-on signal K of "0" at the storage position of the shift register 20 corresponding to the tone generation channel to which the release key is assigned.
Rewritten to ON.

In this way, the CPU 10 performs the sound allocation for the new pressed key and the sound allocation for the new released key, and then detects each operator state in the control switch circuit 14 by sequential scanning in step 1003. In this case, according to the detection result of each operator 140-145, each register REG ₂ in the RAM 12 shown in FIG.
Prescribed data is stored in each of ~ REG ₄ , REG ₆ ~ REG ₈ .

Next, the processing proceeds to step 1005, in which a predetermined tone color parameter TCP _k and envelope data E corresponding to the tone color selected by the tone color selection operator group 146 and corresponding to the tone range of the depressed key assigned to each sounding channel.
NVD _k is read from the ROM 11 for each sounding channel, sent out to the data bus, and stored in each storage position of the shift register 23 via the interface circuit 22.

Next, the CPU 10 calculates the pitch modulation waveform data PMD for obtaining the vibrato effect in step 1006. That is, the detailed flow chart is shown in FIG. 7. First, in step 1100, the CPU 10 sets the current value PHD of the modulated wave phase data register REG ₁ and the operator 141 and stores it in the register REG _2. And the speed data SPD that is present, and the added value "PHD + SPD" is added to the new modulated wave phase data P
It is again stored in the register REG ₁ as HD. Next, in step 1101, this new modulated wave phase data P
The sample point amplitude value PMW (PHD) of the pitch modulation waveform in the phase corresponding to the data PHD is read from the waveform table WT ₁ by HD, and the next step 11
02, the delay data DLSD of the delayed vibrato effect set by the operator 142 and stored in the register REG ₃ and the time elapsed after the first key is pressed from the state in which no key is pressed. The data t shown is multiplied to calculate the delay data DLD according to the lapse of time after the first key is pressed. That is, in step 1102, the CPU 10 sequentially changes the value with the lapse of time after the first key is pressed as shown in FIG. 9 (a), and the change width of this value is set by the operator 142. The delay data DLD for the delayed vibrato effect controlled by the delayed data DLSD thus calculated is calculated.

Next, in step 1103, the CPU 10 operates the operator 140
The depth data DEPSD set in step 1102 and stored in the register REG ₄ are multiplied by the delay data DLD calculated in step 1102, and the depth data DEPS changes with time as shown in FIG. 9 (b). Then, in the next step 1104, the depth data DEP is multiplied by the sample point amplitude value PMW (PHD) of the pitch modulation waveform calculated in the previous step 1101, and the multiplication value PMW (PHD) .DEP is calculated. The modulated waveform data PMD is sent from the data bus in step 1007 of FIG. 6 and stored in the pitch data output register 16.

Next, the CPU 10 calculates the amplitude modulation waveform data LMD for obtaining the repeat effect in step 1008. That is, as shown in the detailed flow chart in FIG. 8, first, at step 1110, the current value PHD of the modulated wave phase data register REG ₅ and the manipulator 14 are set.
4 and the speed data SPD stored in the register REG ₆ are added, and the added value “P
“HD + SPD” is again stored in the register REG ₅ as new modulated wave phase data PHD for the repeat effect. Next, in step 1111 the amplitude modulation in the phase corresponding to this data PHD is made from the waveform table (any of WT _{2 to} WT ₅ ) storing the waveform specified by the operator 145 by this new modulated wave phase data PHD. The sample point amplitude value LMW (PHD) of the waveform is read out, and is set by the operator 143 in the next step 1112.
The depth data DEPSD for the repeat effect stored in the register REG ₇ and the sample point amplitude value LMW of the amplitude modulation waveform calculated in the previous step 1112
(PHD) is multiplied to calculate the amplitude modulation waveform data LMD. Thereafter, in step 1009 of FIG. 6, this amplitude modulation waveform data LMD is sent out from the data bus,
It is stored in the level data output register 15.

The CPU 10 uses the pitch modulation waveform data PMD as described above.
And the calculation processing of the amplitude modulation waveform data LMD is executed every time the processing shown in the flowchart of FIG. 6 completes one cycle.

Therefore, the modulated wave phase data PHD for the vibrato effect and the repeat effect are updated by the values of the speed data SPD set by the operators 141 and 144 each time the processing shown in FIG. 6 completes one cycle. , New sample point amplitude values PMW (PHD) and LMW (PHD) of the pitch modulation waveform and the amplitude modulation waveform are designated for each cycle. As a result, the pitch modulation waveform data PMD and the amplitude modulation waveform data LMD whose values change with time corresponding to the pitch modulation waveform and the amplitude modulation waveform are obtained. In this case, the rate of change of the pitch modulation waveform data PMD and the amplitude modulation waveform data LMD is the speed data SP.
It becomes faster in proportion to the size of D. Therefore, if the speed data SPD is set to a large value, the pitch modulation waveform data PMD and the amplitude modulation waveform data LM having a short repetition cycle are set.
D is obtained.

Pitch modulation waveform data PMD obtained as described above
Is supplied to the adder 241 of the phase data generation circuit 24.
Further, the amplitude modulation data LMD is supplied to the multiplier 27. As a result, the frequency number F corresponding to the pitch of the pressed key output from the frequency number memory 240 is modulated by being added to the pitch modulation waveform data PMD, and the tone generator 26 produces a pitch. A tone signal Gk (t) corresponding to the pitch of the pressed key is generated according to the time change of the modulation waveform data PMD. The tone signal Gk (t) is amplitude-modulated by being multiplied by the amplitude-modulation waveform data LMD in the multiplier 27. As a result, the sound system 28 outputs a musical tone whose pitch changes with the time change of the pitch modulation waveform data PMD and whose amplitude changes with the time change of the amplitude modulation waveform data LMD. That is, the musical sound to which the vibrato effect and the repeat effect are added is sounded.

The cycle in which the processing shown in FIG. 6 makes one cycle differs slightly depending on whether the key operation state is changed or not. Therefore, the changing speed of the modulated wave phase data PHD for the vibrato effect and the repeat effect is also changed. It will be slightly different as the cycle cycle changes. Therefore, when it is necessary to control the pitch modulation and amplitude modulation speeds with high accuracy, a timer process may be added to keep the cycle of the process in FIG. 6 constant. If it is not necessary to set the envelope data and the tone color parameter data for each tone generation channel, only a register for storing the envelope data and tone color parameter data common to all the channels is provided instead of the interface circuit 22 and the shift register 23. Good.

In the above-described embodiment, the modulated waveform data (P
The case where the pitch and amplitude of the musical tone are modulated by the MD, LMD) has been described, but the present invention is not limited to this, and the tone color of the musical tone may be modulated.

〔The invention's effect〕

As described above, in the present invention, since the modulation waveform data is calculated by using the arithmetic processing unit that operates according to the stored program, it is possible to generate a musical sound to which a modulation effect such as a vibrato effect is added with a simple configuration. It can occur and the content of the modulation effect can be easily changed.

In addition, in the present invention, in consideration of "modulation waveform data does not have to be generated in such a short period", one processing unit includes a process according to an operation of a performance keyboard and a process for calculating modulation waveform data. Since it is performed in step 1, there is no need to provide a separate circuit to calculate the modulation waveform, and the configuration can be further simplified.

Further, according to the present invention, since the calculation of the modulation waveform data is performed, the time required for the process of calculating the modulation waveform data can be shortened, and the reduction of the processing speed of the process according to the key operation can be prevented. it can.

[Brief description of drawings]

FIG. 1 is an overall block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing an example of a detailed configuration of the control switch circuit in FIG. 1, and FIG. 3 is a detail of the interface circuit in FIG. FIG. 4 shows an example of such a structure, FIG. 4 is a memory map showing the structure of the ROM shown in FIG. 1, FIG. 5 is a memory map showing the structure of the RAM shown in FIG. 1, and FIGS. 6 to 8 are shown in FIG. FIG. 9 is a graph showing the processing contents of the CPU, and FIG. 9 is a graph showing how the delay data and the depth data change with time. 10 ... CPU, 11 ... ROM, 12 ... RAM, 1
3 ... keyboard circuit, 14 ... control switch circuit,
15 ... Level data output register, 16 ... Pitch data output register, 24 ... Phase data generation circuit, 26
...... Tone generator, 27 …… Multiplier.

Claims (2)

[Claims] 1. A performance keyboard, a modulation waveform designating means for designating a frequency and a depth of a modulation waveform, a tone forming means, and a modulation waveform memory storing amplitude values of a plurality of continuous sampling points of the modulation waveform. A modulation waveform data storage means for temporarily storing the modulation waveform data, a program memory in which a key processing program and a modulation waveform processing program for calculating the modulation waveform data are stored in advance, and one arithmetic processing unit of a stored program system. , (A) according to the key processing program, (1) a process of outputting key information corresponding to a key pressed based on a pressed state of the playing keyboard to the tone forming means, and (B) the modulated waveform According to the processing program (1) Sampling point amplitude values are sequentially output from the modulation waveform memory at a speed corresponding to the frequency of the modulation waveform designated by the modulation waveform designating means. (2) Modulation waveform indicating each sample point of the modulation waveform by controlling the level of the read sample point amplitude value according to the depth of the modulation waveform designated by the modulation waveform designating means. The musical tone forming means corresponds to the key information, the processing of sequentially calculating data, and (3) the processing of sequentially storing the modulated waveform data in the modulated waveform data storage means And modulating at least one of various musical tone elements such as pitch and amplitude according to the modulated waveform data stored in the modulated waveform data storage means to form a musical tone signal with a modulation effect. An electronic musical instrument characterized by. 2. The electronic musical instrument according to claim 1, wherein the arithmetic processing unit repeatedly executes the processing according to the modulation waveform processing program at substantially constant intervals.