JP2532424B2 - Waveform signal input controller - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a waveform signal input control device employed in an electronic musical instrument such as an electronic guitar.

BACKGROUND OF THE INVENTION Conventionally, a basic pitch frequency (hereinafter, simply referred to as a pitch) is extracted from a waveform signal generated by a performance operation of a natural musical instrument, and a sound source device including an electronic circuit is controlled to artificially generate a musical tone or the like. There have been various developments to obtain the sound of.

In this type of electronic musical instrument, it is common to extract the pitch of an input waveform signal and then instruct a sound source device to generate a scale tone corresponding to the pitch.

By the way, in this type of device, even if a pitch change command for frequently changing the pitch is sent to the sound source device,
The sound source device side cannot follow it. In particular, when the pitch of the generated sound is determined based on the pitch information that represents the pitch of a semitone or less, the processing time required to process one pitch change command of the sound source device becomes long, and Even though the processing for the command was not completed, a new command would arrive.

Therefore, in order to avoid this kind of problem, it has been considered that the resolution of the pitch information that specifies the pitch is made coarse (in an extreme case, a semitone is the minimum unit) for processing. In such a processing form, there is a problem that subtle pitch changes and vibrato cannot be expressed.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to improve the pitch resolution and achieve a musically good performance form on the controlled side without imposing a burden on the sound source device. An object of the present invention is to provide a waveform signal input control device.

SUMMARY OF THE INVENTION That is, according to the present invention, once the sound generation start command or the pitch change command is sent, the determination means determines that a predetermined time sufficient to complete the processing for the command has elapsed. The main point is that a new pitch change command is not sent out and the judgment of the passage of the predetermined time is made, and that a new pitch change command is given based on the pitch detected at that time. .

Therefore, the sound source device side sends the pitch change command at least at a predetermined time, so that the process can be performed without difficulty, and the pitch resolution of the music sound is increased regardless of the processing speed. Can be done).

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

Circuit Configuration FIG. 1 shows the circuit configuration of the same embodiment. In this embodiment, the present invention is applied to an electronic guitar, and signals of six input terminals 1 are spread on an electronic guitar body. It is a signal from a pickup provided on each of the six strings provided, which converts the vibration of the string into an electronic signal.

The waveform signal from input terminal 1 ... is the pitch extraction circuit P ₁
~ P ₆ (In some cases, the internal structure is shown _only for P ₁ of the first string.) It is amplified by each internal amplifier 2 ……, and the high-frequency component is cut by the low-pass filter (LPF) 3 ……. Maximum peak detection circuit (MAX) with basic waveform extracted
4 ..., minimum peak detection circuit (MIN) 5 ... and zero-cross point detection circuit (Zero) 6 ... The low-pass filter 3 ... is 4 of the vibration sound frequency f of the open string of each string.
The cutoff frequency is set to 4f. this is,
This is based on that the frequency of the output sound of each string is within 2 octaves. The maximum peak detection circuit 4 ... Detects the maximum peak point of the waveform signal, and the flip-flop 14 connected to the subsequent stage at the rising edge of the detected pulse signal.
The Q output of ... becomes High level, and this flip-flop
The AND output of the output of 14... And the inverted output of the inverter 30 of the zero-crossing point detection circuit 6.
… Via CPU 100 as interrupt command signals INT _{a1 to} INT _a6
Similarly, the minimum peak detection circuit 5 ... Detects the minimum peak point of the waveform signal, and the flip-flop 15 connected to the subsequent stage at the rising edge of the detection pulse signal.
The Q output of ... becomes High level, and this flip-flop
The AND output of the output of 15 ... And the output of the zero-cross point detection circuit 6 ... Is given to the CPU 100 as the interrupt command signals INT _{b1 to} INT _b6 via the AND gate 25.

That is, the maximum peak point is detected and the flip-flop 14
Is high level, when the waveform crosses from positive to negative, that is, when the zero-cross point is detected, the interrupt command signals INT _{a1 to} INT _a6 are given to the CPU100, and conversely the minimum peak point is detected and the flip-flop 15 Is high level, when the waveform changes from negative to positive, that is, when the zero-cross point is detected, the interrupt command signals INT _{b1 to} INT _b6
Enter 00.

Immediately after the CPU 100 receives these interrupt command signals, the corresponding flip-flops 14 ..., 15 ...
On the other hand, clear signals CL _{a1 to} CL _a6 and CL _{b1 to} CL _b6 are generated and reset. Therefore, no matter how many times the zero-cross point is detected until the next maximum peak point or minimum peak point is detected, the corresponding flip-flops 14..., 15. Become.

Note that FIG. 2 shows a time chart of the signal waveform of each part in the pitch extraction circuit P _{1. In} the figure, the output of the low-pass filter 3, the output of the maximum peak detection circuit 4, and the output of the minimum peak detection circuit are shown. The output of 5 is the output of the zero-cross point detection circuit 6.

Then, in the CPU 100, an interrupt command signal INT _{a1 to} INT _a6 or INT _{b1 to} INT _b6 is given by the vibration output of the string, so that a scale sound according to at least one of the time intervals is generated. A musical tone instruction is given to the tone generator circuit 9. At the start of the sound generation, an open string scale sound may be started to be generated, and the frequency may be corrected to a correct frequency after the pitch extraction. The operation at the start of sound generation will be described later.

Then, the above-mentioned time interval is set by the counter 7 as described later.
And the work memory 101. That is, the work memory 101 stores various data such as the count value of the counter 7 at the time of the zero crossing point immediately after the maximum peak point or the minimum peak point.

After the start of sound generation, the frequency of the musical tone being generated is variably controlled according to the time interval data that is sequentially obtained. The pitch change command is given to the tone generator circuit 9 after the timer 8 measures a predetermined time, that is, a time corresponding to the time when one process is completed in the tone generator circuit 9. That is, the timer 8 is CP
Control signal from the U100 is supplied, after measuring a predetermined time, the interrupt command signal INT _c applied to the CPU 100, CPU 100 performs a predetermined interrupt process by the interrupt command signal INT _c. The details will be described later. As a result, a tone signal having a corresponding frequency is generated from the tone generator circuit 9, and the sound system 10 outputs the sound.

The tone signals from the low pass filters 3 ... Are given to the A / D converters 11 ... And converted into digital data corresponding to the waveform level.

And the output of this A / D converter 11 ... Latch 12
Latched on. The latch signal for the latch 12 ... Is generated by the output of the flip-flops 14 ..., 15 ... through the OR gate 13 ..., and is output to the latch 12 ... whenever the maximum peak point or the minimum peak point is passed. Stores a signal indicating the level of the waveform at that time. Also,
Latch signals L _{1 to} L ₆ from this OR gate 13 ... are CPU100.
Also given to.

The outputs of the latches 12 are supplied to the CPU 100, and the control of the start and stop of sound generation, and the sound emission level (volume) of the output sound is performed according to the data.

That is, in the CPU 100, when the absolute value of the data indicating the waveform level given from the A / D converter 11 ...
When this data exceeds a certain value, a mute instruction is given to end the sound emission. The details of the operation are as described later.

Although the A / D converter 11 is independently provided in each of the pitch extraction circuits P _{1 to} P ₆ in FIG. 1, it is of course possible to use one A / D converter in a time division manner. is there.

The sound source circuit 9 performs at least 6
A tone generation system for channels is formed.

Operation Next, the operation of this embodiment will be described. Figure 3 shows CPU1
FIG. 4 is a flow of an interrupt routine for the interrupt command signals INT _a and INT _b of 00, and FIG. 4 is a flow of an interrupt routine for the interrupt command signal INT _c of the CPU 100.
The figure is the main flow. Although FIG. 3 to FIG. 5 only show the processing for one string, the processing for all strings is exactly the same, so it can be considered that the CPU 100 executes the processing for each string in a time division manner. .

Before describing the specific operation of the CPU 100, main registers in the work memory 101 will be described.

The STEP register takes four stages of 0, 1, 2, and 3, and as string vibration is made (see FIG. 6 (a) or FIG. 7 (a)), FIG. 6 (b) or FIG. 7 ( The contents change as shown in b). When the STEP register is 0, it indicates a note-off (silence) state.

The SIGN register indicates whether the zero-cross point for period measurement is the next zero-cross point after the maximum peak (MAX) point or the next zero-cross point after the minimum peak (MIN) point. When the latter comes in.

The REVERSE register is a register for storing data for checking whether or not interrupt processing has been performed due to arrival of a zero cross point after the peak point on the side opposite to the zero cross point represented by the SIGN register has elapsed.

The T register stores the value of the counter 7 at a specific point for measuring the cycle of the input waveform. The counter 7 is performing a free running operation of counting with a predetermined clock.

The AMP (i) register is latched by the D / A converter 11 to the latch 12
A register for storing the maximum or minimum peak value (actually, an absolute value) latched by the AMP (1) is for the maximum peak, and AMP (2) is for the minimum peak.

Data representing the measured period is input to the PERIOD register. Based on the contents of this register, the CPU 100 performs pitch extraction and finally controls the frequency of the tone generator circuit 9.

The FLAG register is 0 when the timer 8 has measured a predetermined time.
Is a control register that becomes 1 before that.

The P and P'registers are pitch storage registers for storing frequency data representing the extracted pitch (which also expresses the value of the frequency range of a semitone or less).

Further, as will be described later, in this embodiment, for various judgments,
Three constants (threshold levels) are set in the CPU100.

The first one is ONLEV I, which is in the note-off state as shown in FIGS. 6 (a) and 7 (a), and when a peak value larger than this ONLEVI value is detected,
Assuming that string picking etc. was performed, the operation for period measurement
The CPU 100 starts executing.

ONLE II is in the note-on state (while sounding), and if the difference between the previous detection level and the current detection level is more than this value, it is determined that there was an operation by the tremolo playing method, etc.
This is for performing the pronunciation start (relative on) process again.

As shown in FIG. 8A, the OFFLEV is in the note-on state (sounding), and when a peak value less than this value is detected, the note-off (silence) processing is performed.

From the above description, it will be easy to understand the operation of the interrupt routine and main routine described below.

Now, the zero-cross point detection interrupt command signals INT _a and INT _b output from the AND gate 24 or 25.
When the CPU arrives at the CPU 100, the interrupt processing shown in FIG. 3 is performed.

That is, the interrupt command signal to the INT _a at the input, first the process in step P _1, the a register in the CPU100 to 1, an interrupt command signal INT _b On input, first the process in step P ₂ in the a register 2 Set.

And then at step P _3, the t registers in CPU 100, presets the value of the count 7. In the subsequent step P ₄ , the peak level data of the A / D converter 11 is read from the latch 12 and set in the b register in the CPU 100.

Then, in step P ₅ , the flip-flop 14 or the flip-flop 15 is cleared.

In the following step P ₆ , the contents of the a, b, and t registers are transferred and stored in the work memory 101, and the interrupt processing is ended.

Further, when the arrival of the interrupt command signal INT _c performs interrupt processing shown in FIG. 4. That is, the content of the FLAG register is set to 0 in step S1. Then, this interrupt processing is ended.

In the main routine (FIG. 5), the contents of a ', b', and t '(the same as a, b, and t above) were previously recorded in the work memory 101 in step Q ₁ by the interrupt processing as described above. Therefore, it is judged whether or not (a ', b', t ') has been written. If no interrupt processing is performed, a NO judgment is made and this step Q ₁
Is repeatedly executed.

Then, if YES is determined in the above step Q ₁ , the process proceeds to the next step Q ₂ and the contents a ', b', t'are read out. In step Q _3, the AMP (a ') register are stored in, that the same type (maximum / minimum) reading the peak value of the peak point to the c register in CPU100 of this extracted peak value b' Is set in the AMP (a ') register.

Now, next step Q ₄ to Q _6, the contents of the STEP register is judge whether each 3,2,1. Now, if it is the first state, since the STEP register is 0, it is judged NO in steps Q ₄ , Q ₅ , and Q ₆ . Then, in step Q ₇ , the peak value b ′ detected this time is turned ON.
Judge whether it is greater than LEV I.

If the peak value b'is smaller than ONLEV I,
Since the process of starting sound generation is not performed, the process returns to step Q ₁ .
Assuming that an input larger than ONLEV I is obtained as shown in FIGS. 6 (a) and 7 (a), the determination in step Q ₇ is
YES, the process proceeds to step Q _8.

Then, in step Q ₈ , 1 is set in the STEP register, then 0 is set in the REVERSE register in step Q ₉ , and then in step Q ₁₀ , a ′ (that is, 1 at the zero cross point immediately after the maximum peak point, the minimum At the zero-cross point immediately after the peak point, enter the value in 2) into the SIGN register.

Then, in step Q _11, it sets the value of t 'to the T register. As a result, the contents of a'are stored in the SIGN register (SIGN is now 1 (FIGS. 10 (a) and 11 (a))), the contents of b'are stored in the AMP register, and the contents of t '. Has been set in the T register. Then go back to step Q ₁ .

Now, with the above description, the processing of the main routine immediately after the zero-cross point Zero1 in FIGS. 6 (a) and 7 (a) is completed.

Now, the process in the main routine immediately after the zero-cross point Zero2 will be described. In that case, the above step Q ₁ →
Execute Q ₂ → Q ₃ → Q ₄ → Q ₅ → Q ₆ and YES at this step Q ₆ .
Judgment is made, and then step Q ₁₂ is proceeded to.

Now, when the waveform changes in the positive direction at the time of input as shown in FIGS. 6 (a) and 7 (a), the SIGN register is 1, and since the peak in the negative direction has passed this time, a ' Since the register is 2, judge NO. Incidentally, if the time arrives zero-cross point immediately after the peak value of the same polarity, step without operation continues any by the determination of YES in step Q ₁₂
Back to Q _1.

Well, now snow to step Q ₁₃ is the judge of Step Q ₁₂ in NO, the STEP register and 2. (See FIG. 6 (b) and FIG. 7 (b)).

Then run the step Q ₁₄ following the step Q _13, compares the previous peak value (AMP (SIGN)) between the current peak value (b '). Now, as shown in FIG. 6A, if the previous value x ₀ is smaller than the current value (x ₁ > x ₀ ), the determination result is YES, and the current time t ′ is set as the measurement start point of the cycle ( Sixth
Perform step Q _10, Q ₁₁ from FIG. (C) refer) Step Q _14, transfers the contents of t 'register with the SIGN register and 2 into the T register.

REVERSE Conversely, larger than the previous peak value current peak value, i.e. if x ₁ <x ₀ as FIG. 7 (a), in step Q ₁₅ and the judge NO in step Q ₁₄ Set the register to 1. The value of the SIGN register is 1
Will be kept. Therefore, in this case, the previous zero-cross point (Zero1) is the starting point of the period measurement (see FIG. 7 (c)).

Then, after passing through the next zero cross point (Zero3), first when performing the main flow, YES in step Q ₅
Backed by a judge to proceed to step Q _16. This time a'is 1
In the case of FIG. 6, SIGN is 2, and in the case of FIG. 7, SI is
Since GN is 1, in the case of Fig. 6, step Q ₁₆
In is the judge NO, the snow step Q to step Q ₁₅
Return to ₁ . That is, the CPU 100 recognizes that it has passed the first peak (amplitude x ₂ ) since the start of the period measurement.

Also in a case of Figure 7, it is a determination of YES in step Q _16, snow REVERSE register is 1 to step Q ₁₇
Judge whether or not. If not 1 but returns to step Q ₁ and the determination NO, the through execution of step Q ₁₅ as described above and snow STEP register 3 to the register Q ₁₈ (FIG. 7 (b) reference), followed by step At Q ₁₉ , t '
Counter 7 received in the register for this interrupt
The value in the T register, that is, the time of the zero-cross point Zero is subtracted from the value of and is stored in the PERIOD register.

That becomes a length of size of one cycle shown in FIG. 7 (c), the contents of t 'in the following step Q ₂₀ are transferred to the T register to the start of a new period measurement.

Then at subsequent step Q _40, calculates a pitch of a musical tone to be generated based on the content of the PERIOD register, (some information that specifies or it) is allowed to record the P 'register pitch frequency information representing it. It is desirable that this pitch frequency information expresses not only octaves and scales but also pitches of a semitone or less in units of cents, for example.
In step Q ₂₁ that follow, with the contents of the above-described P 'register CPU100 issues a sound command to the tone generator 9.
Therefore, a musical sound is generated from this point. Continue to step Q ₄₁ Control the timer 8 to count for a predetermined time, start the timer 8, and continue to step Q _42.
Sets 1 to the FLAG register.

Now, in the case of Figure 6 described above, again in the processing of the main flow after the next zero cross point (ZERO4), it jumps from step Q ₅ to step Q _16. Now, SIGN register is 2, a determination of YES in step Q _16, continues in the same manner as described above Step Q ₁₇ and _{→ Q 18 → Q 19 → Q} 20 → Q 40 → Q 21
→ Q ₄₁ → Q ₄₂ is executed, and this time, the CPU 100 recognizes the zero-cross points Zero2 to Zero4 shown in FIG. 6 (c) as one cycle, and starts the musical tone of the frequency based on this length (Sixth). See FIG. (D)).

In this way, the process of periodic measurement is started from the zero cross point next to the peak point with a large value, and the measurement is finished at the zero cross point next to the peak point on the same side as that peak point. One cycle of a 3-output waveform is extracted.

Then, if after this pronunciation start process, the main routine proceeds from step Q ₄ to step Q _22, the value of b 'is captured peak values this time, exceeds the OFFLEV as shown in FIG. 8 Judge whether or not.

Now, the process proceeds to step Q ₂₃ if I exceeds this level, so as to whether judges whether the processing of the relative-on (reltive on). That is, specifically, it is judged whether or not the current peak value (b ') is larger than the previous peak value (c) by ONLEV II, that is, whether or not the extracted peak value is suddenly increased during sound generation.

If vibration normal strings, since the natural attenuation, this step Q ₂₃ is the determining NO, the the like if tremolo, while the front of the vibrating strings Finished attenuated, that are operated string again rapidly extracting the peak value becomes large by, sometimes resulting determination at step Q ₂₃ is is YES.

In that case, step Q ₂₃ jumps to step Q ₈ and the judge YES, it executes Step Q ₉ to Q _11. As a result, the STEP register becomes 1, and the operation exactly the same as the operation at the start of sounding is executed thereafter. That is, to the process of re-start of sounding running again step _{Q 16 ~Q 20, Q 40,} Q 21, the Q _41, Q ₄₂ thereafter.

In the normal state, as described above, step Q ₂₃ is followed by step Q ₂₄ to compare the contents of a ′ with the contents of the SIGN register. If they do not match, proceed to Q ₁₅ and interrupt the next zero-cross point. For processing, if they match, since peaks (positive / negative peaks) having opposite characteristics have already been passed, proceed to step Q ₂₅ , judge whether REVERSE register is 1 or not, and if NO Return to step Q ₁ without any processing, but if this step Q ₂₅ is YES
If the judgment is made, step Q ₂₅ to step Q ₂₆
In order to obtain a new cycle, the contents of the T register are subtracted from the contents of the t'register and set in the PURIOD register.

Then, in step Q ₂₇ , the contents of the t ′ register are transferred to the T register, and in the following step Q ₂₉ , the contents of the REVERSE register are set to 0, and the next cycle measurement is performed.

In the following step Q ₄ , it is judged whether or not the FLAG register is 0, and if NO, the process returns to step Q ₁ and no pitch change processing based on the cycle data obtained in the PERIOD register is performed as described above. . But step Q ₄₁
If you judge YES at, that is, the timer 8 counts for a predetermined time from the previous sound generation start processing and pitch change processing,
If the interrupt processing (see FIG. 4) is performed, even if the tone generator circuit 9 is newly instructed to perform the frequency change control, the tone generator circuit 9 can accept it and process it appropriately.

Accordingly, then proceeds to step Q _4. This is step Q ₄₀
However, the obtained pitch frequency information is set in the P register. In step Q _45, already frequency information stored in the P 'register, the coincidence comparison between the frequency information stored in the P register currently obtained.

When the coincidence detection is performed, it is not necessary to change the frequency, so the process returns from step Q ₄₅ to step Q ₁ . However, if a mismatch is detected, it is considered that the frequency of the input waveform has changed due to guitar string operations, etc., and the following processing is performed to change the frequency of the output musical sound by following it.
U100 does.

That is, if NO is detected in step Q ₄₅ , step Q
₂₈ , the pitch frequency information etc. in the P register is transferred to the tone generator circuit 9, and the frequency is changed. Therefore, in the tone generator circuit 9, the frequency of the musical tone that has been generated so far is changed to the newly instructed frequency based on the given information.

Then, it continues to step Q _28, CPU 100 is transferred to the P register to P 'register, running thereafter step Q _41, Q _42, ready for the next frequency change process.

In this way, in this embodiment, the change in the vibration frequency of the string is grasped moment by moment, and the frequency control is performed in real time accordingly.

Then, as described above, when the string vibration is attenuated and the peak value falls below OFFLEV as shown in FIG. 8, the process proceeds from step Q ₂₂ to step Q ₃₀ and the STEP register is set to 0, and the following step Q ₃₁ Performs note-off processing (silence processing) at CP to silence the musical tones that have been produced so far.
U100 will give instructions to the tone generator circuit 9.

Since this embodiment performs such processing, the timer 8 is activated after the tone generation start command or the pitch change command is given to the tone generator circuit 9.
Since a new pitch change command is given to the tone generator circuit 9 after a lapse of a predetermined time, that is, a time corresponding to the completion of the processing in the tone generator circuit 9, the CPU 100 and the tone generator circuit 9 have a fine pitch resolution. It is possible to perform sufficient processing regardless of the processing speed related to data exchange with the.

In addition, the new sound generation start and the mute start are immediately responded to by the CPU 100 performing the corresponding processing and giving a predetermined instruction to the sound source circuit 9 when the detection is made, so that the responsiveness is good.

In the above embodiment, the CPU 100 performs interrupt processing at the zero-cross point immediately after each peak point to perform sound generation start, period calculation, relative on, mute start, etc. You may perform these processing directly at the time of leaving. In that case, the exact same result can be obtained.
In addition, the same processing as above may be performed, for example, by detecting the zero-cross point immediately before the peak point. In addition, the way of taking a reference point can be variously changed. Furthermore, there are various circuit patterns for pitch extraction, which may be obtained, for example, by taking the autocorrelation function of the waveform, and any other pitch extraction method can be used.

Further, in the above embodiment, each process is executed in the main flow, but the same process may be executed in the interrupt process.

Furthermore, in the above embodiment, the present invention was applied to an electronic guitar, but it is not necessarily limited to this, by performing pitch extraction from a voice signal or an electric vibration signal input from a microphone or the like, Any form may be used as long as it is a system that generates an acoustic signal different from the original voice signal at a corresponding pitch or scale frequency. Specifically, those having a keyboard, such as an electronic piano, an electronic wind instrument, a string instrument,
For example, it can be similarly applied to a computerized violin or koto.

[Effects of the Invention] As described in detail above, according to the present invention, once the sound generation start command or the pitch change command is transmitted, the judgment means judges the elapse of a predetermined time sufficient to complete the processing for the command. Until a new pitch change command is issued, when it is judged that the predetermined time has elapsed, a new pitch change command is given based on the pitch detected at that time. Thus, it is possible to provide a waveform signal input control device capable of controlling the generation of musical tones with high frequency resolution while keeping the frequency of pitch change command transmission low.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a diagram showing a circuit configuration of the same embodiment, FIG. 2 is a time chart diagram showing waveforms appearing in respective parts in FIG. 1, and FIG. Is a diagram showing a flowchart of the CPU zero-cross point interrupt routine,
FIG. 4 is a flow chart of the timer interrupt routine of the CPU, FIG. 5 is a flow chart of the main routine of the CPU, FIGS. 6 and 7 are time charts showing the operation of each part at the start of sound generation, and FIG. The figure is a time chart showing the operation at the start of muffling. 1 ... Input terminal, 4 ... Maximum peak detection circuit, 5 ... Minimum peak detection circuit, 6 ... Zero-cross point detection circuit, 7 ...
... Counter, 8 ... Timer, 9 ... Sound source circuit, 14,15 ...
… Flip-flop, 100… CPU, 101… Work memory, P1 to P6… Pitch extraction circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-159495 (JP, A)

Claims (1)

(57) [Claims] 1. A waveform having pitch detecting means for detecting the pitch of an input waveform signal and instructing means for instructing to generate a musical tone of a corresponding pitch based on the pitch detected by the pitch detecting means. In the signal input control device, when the above-mentioned instructing means gives a sounding start command or a pitch change command, each time, a judging means for judging the elapse of a predetermined time sufficient to complete the processing for the command, and this judging means Until the predetermined time elapses, it is controlled so that the instruction means does not give a new pitch change command based on the pitch detected by the pitch detection means, and the judgment of the predetermined time elapses. Then, control means for controlling the instructing means to give a new pitch change command based on the pitch detected at that time by the pitch detecting means, Waveform signal input control apparatus characterized by Bei was.