JP2605773B2 - Electronic string instrument - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic stringed instrument such as an electronic bass guitar, and in particular, detects that a popping technique or a pull technique (hereinafter referred to as popping technique) has been performed. The present invention relates to an electronic stringed musical instrument that generates a predetermined sound different from a designated scale sound.

(Prior art)

2. Description of the Related Art Conventionally, various electronic musical instruments have been developed in which a pitch (fundamental frequency) is extracted from a waveform signal generated by a playing operation of a natural musical instrument, and a tone generator or the like is obtained by controlling a sound source device constituted by an electronic circuit. Have been.

One type of electronic musical instrument is an electronic bass guitar or a bass guitar synthesizer, but when popping or the like is performed on such an instrument, a chromatic note different from the chromatic note originally specified by the fret is erroneously made. It starts to occur and then changes to the original scale sound.

That is, the popping playing technique is a playing technique in which the strings are vibrated by hitting the strings with the thumb, and the pull playing technique is a playing technique in which the strings are vibrated by pulling and pulling the strings apart. The pitch extracted first is a sound period different from the fret operation. For this reason, as described above, after a sound of a different frequency appears for a moment, the frequency is changed to the sound of the original scale frequency.

Therefore, there is a problem that a scale tone that is not intended by the player is generated, which is very difficult to hear and that is inconvenient musically.

[Object of the invention]

The present invention has been made in view of the above circumstances, and detects that a popping playing technique or the like has been performed, and first generates a predetermined sound such as a noise sound or a percussion sound in which it is difficult to determine a pitch different from the scale sound. It is an object of the present invention to provide an electronic stringed musical instrument.

[Gist of the invention]

In order to achieve the above object, the present invention provides a polarity detecting means for detecting whether a first wave of an input waveform signal generated at the time of a string operation has a predetermined polarity, and a peak of the first wave of the input waveform signal. A peak level detecting means for detecting a plurality of peak levels having the same polarity following the first wave and detecting whether or not these peak level groups are sequentially reduced; and a period of the input waveform signal. Pitch designation means for designating a pitch based on the pitch, and normally instructing the generation of a musical tone having the pitch designated by the pitch designation means, and the polarity detection means causes the first wave of the input waveform signal to be generated. If it is detected that the polarity is a predetermined polarity, and if the peak level detecting means detects that the peak level group is sequentially decreasing, the generation of a predetermined sound different from the musical tone instructed to generate the sound is performed. A sounding instruction means for instructing, and main point by comprising a.

Therefore, the performance style is detected from a unique input waveform signal such as a popping performance style, and the above-described noise sound and percussion sound are output at the beginning of musical tone generation. , The scale sound is generated.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking an example in which the present invention is applied to an electronic bass guitar. However, the present invention is not limited to this and can be similarly applied to other types of electronic stringed instruments. .

FIG. 1 is a block diagram showing an entire circuit. Pitch extraction analog circuits PA are respectively provided on six strings stretched on an electronic bass guitar body (not shown), for example.
Hex pickup that converts string vibration into electric signal,
A zero-cross signal and a waveform signal Zi, Wi (i = 1 to 6) are obtained from the output from the pickup, and these signals are converted into a time-division serial zero-cross signal ZCR and a digital output (time-division waveform signal) D1. Conversion means, for example, an analog-digital converter A / D is provided.

The pitch extraction digital circuit PD includes a peak detection circuit PEDT, a time constant conversion control circuit TCC, a peak value acquisition circuit PVS, and a zero cross time acquisition circuit ZTS as shown in FIG. 2, and a serial zero cross from the pitch extraction analog circuit PA. signal
The maximum peak point or the minimum peak point is detected based on the ZCR and the digital output D1, and MAX I, MIN I (I = 1 to 6) is generated. An interrupt (interrupt) signal INT is output to the microcomputer MCP upon passing the zero-cross point immediately after, and the time information and peak value information of the zero-cross point such as MAX and MIN are output.
And output the instantaneous value of the input waveform signal to the microcomputer MCP. Note that a circuit is provided inside the peak detection circuit PEDT for holding while subtracting a past peak value.

The time constant conversion control circuit TCC changes the decay rate of the peak hold circuit of the peak detection circuit PEDT. When a peak cannot be detected even after a lapse of, for example, one cycle of the waveform, the decay rate is rapidly reduced. To do it. Specifically, in the initial state, the waveform rapidly attenuates after the maximum sound period elapses in order to quickly detect the vibration of the waveform, and does not pick up harmonics when the string vibration is detected. Similarly, rapid decay is performed over time, and after the vibration period of the string is extracted, rapid decay is performed at that period.

The setting of the period information for the time constant conversion control circuit TCC is performed by the microcomputer MCP. Then, each string-independent counter in the time constant conversion control circuit TCC is compared with the set period information for coincidence, and a time constant change signal is sent to the peak detection circuit PEDT when the period time elapses.

The peak value capturing circuit PVS in FIG. 2 performs a demultiplexing process on the waveform signal (digital output) D1 transmitted in a time-division manner as described above into a peak value for each string, and outputs the peak signal from the peak detection circuit PEDT. MAX I, MIN I
Hold the peak value according to. And the microcomputer
The MCP outputs the maximum peak value or the minimum peak value of the string accessed through the address decoder DCD to the microcomputer bus. The peak value capturing circuit PVS can also output the instantaneous value of the vibration of each string.

The zero-cross time acquisition circuit ZTS latches the output of the time base counter common to each string at the zero-cross point of each string (strictly speaking, the zero-cross point immediately after passing the maximum peak point and the minimum peak point). Then, in response to a request from the microcomputer MCP, the latched time information is transmitted to the microcomputer bus.

Further, a timing signal for the processing operation of each circuit shown in FIGS. 1 and 2 is output from the timing generator TG shown in FIG.

The microcomputer MCP has a memory, for example, a ROM and a RAM, and also has a timer T, and controls a signal to be supplied to the sound source generator SOB. Sound source generator SOB
Is sound source SS, digital-analog converter D / A, and amplifier AMP
And a speaker SP, and emits a musical tone having a pitch corresponding to a pitch instruction signal for changing the frequency from note-on (sound generation) to note-off (silence) from the microcomputer MCP.
Between the data bus BUS input side and the microcomputer MCP sound source SS, an interface (M usical I nstrument
D igital I nterface) MIDI is provided. Of course,
When providing the sound source SS on the guitar body, another interface may be used. When an address read signal AR from the microcomputer MCP is input, the address decoder DCD receives a string number read signal RDI and a time read signal RDj (j =
1 to 6), the peak values of MAX and MIN, and the instantaneous value read signal RDA I (I = 1 to 18) at that time are output to the pitch extraction digital circuit PD.

Hereinafter, the operation of the microcomputer MCP will be described with reference to flowcharts and drawings showing waveforms. First, reference numerals in the drawings will be described.

AD: input peak value (instantaneous value) directly reading the input waveform of the pitch extraction digital circuit PD using the instantaneous value read signals RDA13 to RDA18 in FIG. 1 AMP (0,1) ... positive or negative previous (old) wave High value AMRL1 ... relative (rel) stored in the amplitude register
ative) The previous amplitude value for checking off. Here, the relative off is equivalent to a silencing process when the fret operation is stopped and the sound is shifted to an open string by canceling the sound based on a sudden decrease in the peak value.

AMRL2 ... in the amplitude value of the second last for the relative-off stored in the amplitude registers, including the value of AMRL ₁ is input.

CHTIM: The cycle corresponding to the highest tone fret (22th fret) CHTIO: The cycle corresponding to the open string fret CHTRR: A time constant conversion register, which is provided inside the time constant conversion control circuit TCC (FIG. 2). .

DUB: A flag indicating that the waveforms continuously came in the same direction FOFR: Relative off counter HNC: Waveform number counter MT: Flags from which the pitch is to be extracted (positive = 1, negative =
0) NCHLV: No change level (constant) OFTIM: Off time (e.g., corresponding to the open string cycle of the string) OFPT: Normal off-check start flag ONF: Note-on flag PP: 1, when popping performance is performed A flag that changes to 2 RIV: A flag for switching the processing route in step (STEP) 4 described later ROFCT: A constant that determines the number of relative off checks STEP: Registers (1 to 5) that specify the flow operation of the microcomputer MCP ) TF: Last valid zero-cross time data TFN (0,1): Previous zero-cross time data immediately after positive or negative peak value TFR: Time storage register THLIM: Upper frequency limit (constant) TLLIM: Lower frequency limit (constant) TP (0,1) ... positive or negative previous cycle data TALAB (0,1)… positive or negative absolute trigger level (note-on threshold) TRLRL… relative on ) Threshold TRLRS: resonance removal threshold TTLIM: lower frequency limit at the time of trigger TTP: cycle data extracted last time TTR: cycle register TTU: constant (product of 17/32 and current cycle information tt) TTW: constant (Product of 31/16 and current cycle information tt) VEL: Information that determines the velocity (velocity), and is determined by the maximum peak value of the waveform at the start of sound generation.

X: Flag indicating an abnormal or normal state b: Current positive / negative flag stored in the working register B (1 at the next zero point after the positive peak, 0 at the next zero point after the negative peak) c: Working register C The current peak value (peak value) stored in the working register E; the pre-last peak value (peak value) stored in the working register h; the periodic data extracted before and after the last time stored in the working register t; the working register T0 The current zero-crossing time stored in the register tt ... The current cycle information stored in the working register TOTO FIG. 3 is an interrupt routine showing processing when an interrupt is applied to the microcomputer MCP. The MCP sends the string number read signal RDI to the zero-cross time acquisition circuit ZTS via the address decoder DCD.
To read the string number specifying the string that gave the interrupt. Then, the time information corresponding to the string number, that is, the zero-cross time information, is supplied to the zero-cross time fetch circuit ZTS by giving any one of the time read signals RD1 to RD6. This is defined as t. Thereafter, at I2, the peak value reading signal RDA I (I
= 1 to 12) and read the peak value. This is assumed to be c.

In the following I3, information b indicating whether the peak value is a positive or negative peak is obtained from the zero-crossing time acquisition circuit ZTS. And at I4, I got it this way
The values of t, c, b are stored in the registers TO, C, B of the buffer in the microcomputer MCP.
Set to. Each time interrupt processing is performed, such time information, peak value information, and information indicating the type of peak are written into this buffer as one set, and the main routine processes the information for each string. Is made.

FIG. 4 is a flowchart showing a main routine. When the power is turned on, various registers and flags are initialized in M1, and the register STEP is set to 0. At M2, it is determined whether or not the above-mentioned buffer is empty. If NO (hereinafter referred to as N), the process proceeds to M3, and the contents of the registers B, C, and TO are read from the buffer. As a result, in M4, several registers STEP are determined, and M5
In Steps 0 and M6, the processing in Step 1, Step 7 in M7, Step 3 in M8, and Step 4 in M9 are sequentially performed.

If the buffer is empty at M2, that is, if yes (hereinafter, referred to as Y), the process proceeds sequentially to M10 to M16, where normal note-off processing is performed. In the note-off algorithm, note-off is performed when a state below the OFF level continues for a predetermined off-time period. M10
Then, it is determined whether or not STEP = 0, and if N, the process proceeds to M11. In M11, the input peak value AD at that time is directly read. This can be achieved by applying any one of the peak value reading signals RDA13 to RDA18 to the peak value capturing circuit PVS.
Then, it is determined whether or not this value AD is the input peak value AD off level, and if Y, the process proceeds to M12. In M12, it is determined whether or not it is the previous input peak value AD off level, and in the case of Y, the process proceeds to M13, where the timer T value off time O
It is determined whether it is FTIM (for example, a constant of the open string period of the string). In the case of Y, the process proceeds to M14, where 0 is written in the register STEP. In M15, it is determined whether or not the note is on. In the case of Y, the note-off process is performed in M16, and the process returns to M2 via M. If N is M12, proceed to M17
Start the MCP internal timer T and return to M2 via M. In case of Y in M10 and in case of N in M11, M13, M15,
All return to M12 via M.

Thus, when the level of the waveform input is attenuated,
When the input peak value AD equal to or less than the off level continues for a time corresponding to the off time OFTIM, the microcomputer MCP sends a note-off instruction to the sound source SS. In step M15, the determination of Y is made in a normal state, but the register STEP may take a value other than 0 even when the generation of a musical tone is not instructed by the processing described later ( For example, due to noise input.) In such a case, M14, M15
By returning to M2 after the processing of, the initial setting is performed.

Although FIG. 4 shows only the processing for one string, the microcomputer MCP multiplexes the processing shown in this figure six times corresponding to the number of strings. Of course, a plurality of processors may be provided, and the same processing may be executed separately and independently.

Next, the details of the processing of each routine performed by branching at M4 will be described.

FIG. 5 shows a step 0 (STEP 0) shown as M5 in FIG.
0), it is determined in S01 whether the absolute trigger level (note-on threshold) TRLAB (b) <the present peak value c, and if Y, the process proceeds to S02 to check for resonance removal. Is made. The trigger level is checked for each of positive and negative polarity peaks. This TRLAB (0) and TRLAB
(1) is set to an appropriate value by an experiment or the like. In an ideal system, TRLAB (0) and TRLAB (1) may be the same. In S02, it is determined whether or not resonance removal threshold value TRLRS <[current peak value c−previous peak value AMP (b)], that is, whether the difference between the current peak value and the previous peak value is equal to or greater than a predetermined value.

When picking one string causes another string to resonate, the level of vibration of the other string gradually increases, and as a result, the change in the peak value between the previous time and the current time becomes very small. The difference is the resonance rejection threshold
Never exceed TRLRS. However, in normal picking, the waveform suddenly rises (or falls), and the difference between the peaks exceeds the resonance removal threshold value TRLRS.

If it is determined in S02 that the case is not Y, that is, it is not the case of resonance, the following processing is performed in S03. That is, the current positive / negative flag b is written into the flag MT, 1 is written into the register STEP, and the current zero-cross time t is set as the previous zero-cross time data TFN (b). Then, in S04, other flags are initialized, and the process proceeds to S05. In S05, the current peak value c is set as the previous peak value AMP (b), and thereafter, the process returns to the main flow in FIG.

In FIG. 5, A is relative on (reproducing starts).
And jumps to S06 from the flow of STEP 4 described later. Then, in S06, the musical tones that have been output so far are deleted once, and S03 is started in order to start re-generation.
Proceed to. The process for starting re-sound generation is the same as that for starting normal sound generation, and will be described in detail below.

Then, in the case of N in S01 and the case of N in S02 (when the current peak value c-the previous peak value AMP (b) is not equal to or more than the predetermined value), the process proceeds to S05. Accordingly, the process for starting sound generation does not proceed.

In STEP 0 described above (between STEP 0 and 1 in FIG. 11), the contents of the B register (b = 1) are written in the flag MT, and the contents (t) of the register TO are set to the previous zero-crossing time data TFN.
(1) is written, and the peak value (c) of the register C is written to the previous peak value AMP (1).

FIG. 6 shows details of the flowchart of STEP 1 shown as M6 in FIG. 4. In S11, it is determined whether or not the content (b) of the register B and the flag MT do not match.
In the case of, the process proceeds to S12. In S12, it is determined whether or not the absolute trigger level (note-on threshold) TRLAB (b) <the current peak value c. If Y, the process proceeds to S13. In the case of Y in S12, 2 is set in the register STEP, and in S14, the register TO
(T) is replaced with the previous zero-cross time data TFN (b)
Then, in S15, the current peak value c is set to the previous peak value AMP (b). In S11, in the case of N, that is, when the input waveform signal comes in the same direction, the process proceeds to S16, and it is determined whether or not the current peak value c> the previous peak value AMP (b). If it is larger than the peak value AMP (b), the process proceeds to S14. Meanwhile, S12
In the case of N, the process proceeds to S15, whereby only the peak value is updated. In S16, if N, or at the end of the processing in S15, the process returns to the main flow (FIG. 4).

In STEP 1 described above (between STEP 1 and STEP 2 in FIG. 11), since the current positive / negative flag b (= 0) and the flag MT = 1 do not match, the current zero cross time t is set to the previous zero cross time data TFN (0 ), And the current peak value c is written as the previous peak value AMP (0).

FIG. 7 shows details of the flowchart of STEP 2 shown as M7 in FIG. 4. In S20, it is determined whether or not the current positive / negative flag b = flag MT, that is, whether or not the same zero-cross point as the direction of STEP0 has arrived. S201 for Y
Proceed to. In this S201, it is judged whether the player is in a performance state using a pick or in a state in which he is performing performance by picking with his finger.

This can be determined by the player performing input setting in advance by using an external switch provided on the main body of the electronic bass guitar to determine the playing state. Of course, the two types may be determined by other methods.

Shape of input waveform signal generated by string vibration when using this pick, especially peak of negative polarity (MIN)
Is similar to that of the input waveform signal obtained by the above-described popping technique (this has been experimentally confirmed), and since there is not much use of the pick to strike the strings, the pick Use S201 to S22 when using
The processing for popping performance etc. is not executed.

If you are not using a pick, go to S202, b
It is detected whether or not the judgment is = 1 or 0, that is, whether or not the peak is on the negative side. As will be described in detail later, at the time of popping performance, as shown in FIG. 12, for example, the negative side (of course, if the polarity of the coil of the pickup and the positive and negative polarities of the electronic circuit are changed, the positive side can be obtained. , Once the system is set, it will be on one of the fixed polarity sides).
γ) has been experimentally confirmed, and when the judgment of b = 0 (judgement of N) is made in S202 in order to judge the change of the peak of the negative electrode, the process proceeds to S203 and the current peak value c> the previous time It is detected whether the peak value is AMP (0) or not. If it is N, it is determined that there is a possibility that the popping performance technique or the like has been performed for the above-described reason, and the process advances to S204 to set the flag PP to 1.
When the determination of Y is made in S202 and when the determination of Y is made in S203, the process proceeds to S22.

In S22, the current peak value c> (7/8) x the previous peak value AMP
(B) Whether or not the peak value is substantially the same between the previous time and the present time is checked. In the case of Y, that is, in the case of beautiful natural attenuation, the process proceeds to S23, and the flag DUB is set to 0, and the process proceeds to S24.
Proceed to. After executing S204, the process proceeds to S23. In S24, the cycle calculation is performed, the current zero-cross time t-the previous zero-cross time data TFN (b) is input to the previous cycle data TP (b), and the current zero-cross time t is used as the previous zero-cross time data TFN (b). ). S24
Is used as a note-on (1.5 wave) condition in STEP3. In S24, the register STEP is set to 3. Further, the largest value among the current peak value c, the previous peak value AMP (0), and the previous peak value AMP (1) is registered as the velocity VEL. Also, the current peak value c is written to the previous peak value AMP (b). And the next S
At 241, it is determined whether the register PP is 1 or not.
In step 2, the value of the cycle of TP (0) is set in the register CHTRR in the time constant conversion control circuit TCC. When the determination of N is made in step S241, the process proceeds to step S243, where the open string cycle CHTIO is stored in the register CTR.
Set to HTRR. When the popping technique is performed, the peak value is greatly attenuated immediately after the input of the input waveform signal. Therefore, if the open string period CHTIO is set in CHTRR, the second and third peaks may not be detected. Therefore, the processing as described above is performed. This TP (0) is shown in FIG.

In the case of N in S20, the process proceeds to S25, where the flag DUB, that is, the flag indicating that an input waveform in the same direction has arrived, is set to 1, and the process proceeds to S26. In S26, it is determined whether or not the current crest value c> the previous crest value AMP (b).
Proceed to. In S29, the current peak value c is replaced by the previous peak value AMP (b)
And the previous zero-crossing time data TFN (b) is rewritten to the contents t of the register T. In S22,
In the case of N, the flow proceeds to S27, in which it is checked whether or not the flag DUB = 1, that is, when STEP2 was executed last time, and in the case of Y, that is, in the case of double, the flow proceeds to S28. In S28, the flag DUB is set to 0. In this case S29
To return to the main routine. After the processing in S24 and also in the case of N in S26, the process similarly returns to the main routine (RET).

In STEP 2 described above (between STEP 2 and STEP 3 in FIG. 11), the flag MT = 1 is rewritten as the positive / negative flag b, the flag DUB is set to 0, and t-TFN (1) → TP
(1) The cycle calculation is performed, and the previous zero-cross time data TFN (1) is rewritten at the current zero-cross time t, and the current peak value c, the previous peak value AMP (0), the previous peak value A
The largest value of MP (1) is set as velocity VEL, and as the current crest value c, the previous crest value AMP (1)
Is set. Then, it is determined whether or not the popping rendition is performed, and if the content of the register PP is set to 1, TP (0) is set in CHTRR.
CHTIO is set in HTRR.

FIG. 11 shows an example in which there is an ideal waveform input. A case in which DUB = 1 will be described below. FIG. 8 is a diagram for explaining the operation of STEP 2 in such a case. FIG. 8 (A) shows a case where one wave is skipped and a peak is detected. And note-on is not performed when the input waveform is a dotted line. This is due to the difference between Y and N in S26. Also, the reason why it is difficult to shift from STEP 2 to STEP 3 is that even if b = MT is satisfied in S20, c> (7/8) × A in S22.
If MP (b) is determined to be N and this is not Y, ST (ST)
This is because EP2 is repeatedly executed. (B)
This is a case where an overtone lower than an octave is detected. In this case, when c> (7/8) × AMP (b) is checked, Y becomes S2
After 3, go to S24 and move to STEP3.

FIG. 9 is a flowchart of STEP 3 shown as M8 in FIG. 4. In S30, it is determined whether or not the flag MT ≠ the current positive / negative flag b. If normal, that is, if Y, the process proceeds to S31. In S31, if (1/8) c <AMP (b), X is set to 0, otherwise, X = 1 is set, and the process proceeds to S32. In S32, the previous peak value AMP (b) is rewritten as the current peak value c.

Then, in S33, if the current peak value c is larger than the VEL obtained in STEP2, the current peak value c is input as the velocity VEL. If vice versa, this velocity VEL will not change. Next, the flag MT is rewritten to the positive / negative flag b this time, whereby the pitch change side is reversed. This means that the meaning of the flag MT is different from STEP 4 described later, and means a pitch change side. Then, in S34, [t-TFN (b) → TP
(B)]. The current zero-cross time t is used as the previous zero-cross time data TFN.
(B) is rewritten.

Next, in S35, it is determined whether or not X = 0, and in the case of Y, the process proceeds to S36, and whether or not the frequency upper limit THLIM <the previous cycle data TP (b), that is, the pitch extraction upper limit is checked. If the period is longer than the period of the highest sound, it is Y because it is within the allowable range, and the process proceeds to S37. In S37, whether the lower limit of the frequency at the time of the trigger TTLIM> the previous cycle data TP (b), that is, the lower limit of the pitch extraction is checked, and if the cycle is shorter than the cycle of the lowest sound, it is within the allowable range. And proceed to S38. The pitch extraction lower limit of S37 is different from the pitch extraction lower limit of STEP 4 described later in a constant.

Specifically, the upper frequency limit THLIM is equivalent to a pitch period two to three semitones above the highest note fret, and the lower frequency limit TTLIM at the time of triggering is set to a pitch period five semitones below the open string fret of the open string. Shall be equivalent.

In S38, the previous cycle data TP (b) is set as the previously extracted cycle data TTP, that is, the pitch extracted on the pitch extraction side is saved (this is used in STEP4 described later), and the process proceeds to S39. In S39, a 1.5-wave pitch extraction check is performed to check whether or not the previous cycle data TP (b) （TP (), that is, a check of a cycle substantially coincident between zero-cross points having different polarities. Is performed. That is, the time storage register TFR is rewritten as the previous zero cross time data TFN (), the current zero cross time t is set as the previous zero cross time data TF, and the waveform number counter HN
Clear C This counter HNC is used in STEP 4 described later. Register STEP is set to 4 and constant TTU
Is set to 0, ie, (MIN), and the constant TTW is MAX
Is set to These are all used in STEP 4 described later. Also, the previous peak value register AMRL1 for relative off is cleared.

Then, in S310, it is judged whether or not the register PP is 1. If Y, there is a possibility that the popping performance technique or the like has been performed, so that even if the first cycle information is obtained, the process proceeds to STEP4 without performing the note-on.

If a determination of N is made in S310, the process proceeds to S311,
Since there is no suspicion that popping performance or the like has been performed, the note-on flag ONF is set to 2 to bring the note-on state. In subsequent S302, note-on processing is performed with a normal tone at a pitch corresponding to the previous cycle data TP (b) and a volume corresponding to the velocity VEL. That is, the microcomputer MCP instructs the sound source SS to start sound generation.

In S30, in the case of N (in the case of zero-cross point detection in the same direction), the process proceeds to S303, and the previous peak value AMP (b) <
It is determined whether or not this time is the peak value c, and in the case of Y, the process proceeds to S304. In S304, the current peak value c is the previous peak value AMP (b)
And the larger of the velocity VEL and the value c of the register C is set to the velocity VEL. In any of S303, S35, S36, S37, and S39, if N, return to the main routine (RET).

FIG. 18 is a diagram showing a specific example of a case where X = 1, that is, an abnormality, in S31, wherein 1 / 8b ₁ <b ₀ and 1 / 8a ₂
<Both the judge when a ₁ does not satisfy the condition, the X = 1.

That is, the peaks (a ₀ , b) of the first three waveforms in FIG.
₀ , a ₁ ) is caused by noise. If the period of these noises is detected and the start of sound generation is instructed, a completely strange sound is generated. Therefore, in S31, it is detected that the peak value has greatly changed, X = 1, and N is determined in S35. Then, in S31, it is instructed to start sound generation after it is detected that the waveform changes normally.

In the case of FIG. 18, note-on occurs when TP (b) ≒ TP () is detected.

In STEP 3 described above (between STEP 3 and 4 in FIG. 11), the MT
= 1 ≠ b, AMP (0) ← c, max [VEL, c (whichever is greater)] → VEL, MT ← b = 0, TP (0) ← [t−T
FN (0)], TFN (0) ← t, TTP ← TP (0), TFR ← TFN
(1), TF ← t, HNC ← 0, TTU ← 0 (MIN), TTW ← MA
If X, AMRL1 ← 0, and PP = 1, processing for the note-on condition TP (0) ≒ TP (1) is performed. Then, in response to the appropriate waveform input, in this STEP 3, the ONF
← 2, and the generation of a musical tone having a pitch according to the extracted pitch is started. As can be seen from FIG. 11, a sound generation instruction is issued to the sound source SS about 1.5 cycles after the start of the cycle detection. Of course,
If the conditions are not satisfied, further delays are as described above. If PP = 1, no sound is started in STEP3.

FIG. 10 is a flowchart of STEP 4 shown as M9 in FIG. 4, in which a route for performing only pitch extraction,
There is a route to actually change the pitch. And PP =
There is a route to be executed at 1. First, the case where PP = 0 will be described below. That is, S400, S40, S41, S4
2. The routes shown in S63 to S71 will be described first. At S400, N is determined. At S40, the waveform number counter HNC> 3 is determined. If Y is determined, the process proceeds to S41. In S41, it is determined whether or not the relative-on threshold value TRLRL <[current crest value c-previous crest value AMP (b)]. If N, the process proceeds to S42. In S42, it is determined whether or not the current positive / negative flag b = flag MT, that is, the pitch change side.
In the case of Y, the process proceeds to S43.

By the way, in the initial state, the waveform number counter
Since HNC is 0 (see S301 in FIG. 9), N is determined in S40 and the process proceeds to S42. Then, for example, in the case of the waveform input as shown in FIG. 11, since b = 1 and MT = 0, S42
Proceed to S63 from.

In S63, it is determined whether or not the register RIV = 1 to check whether or not a peak having the same polarity is continuously input (whether it is a double). If Y, the process proceeds to S68, and , N (if not double)
Proceeds to S64, where the following processing is performed. That is, in S64, the current peak value c is input to the previous peak value AMP (b), and the previous amplitude value AMRL is used for relative off processing.
1 is input to the amplitude value AMRL2 two times before. In this case, the content of AMRL1 is 0 (see S30 in STEP3). Further, in S64, the previous peak value AMP () and the present peak value c
Is input to the previous amplitude value AMRL1. That is, the larger peak value of the two positive and negative peak values in one cycle is set as the amplitude value AMRL1. Then, in S65, it is determined whether or not the waveform number counter HNC> 8. Here, the waveform number counter (zero cross counter on the non-pitch changing side) HNC is incremented by 1 and counted up.

Therefore, the upper limit of the waveform number counter HNC is 9. Then, the process proceeds to S67 after the process of S65 or S66. In S67, the register RIV is set to 1, the content of the time storage register TFR is subtracted from the current zero crossing time, and the result is input to the period register TTR. This cycle register TTR is
The period information shown in FIG. Then, the current zero cross time t is saved in the time storage register TFR, and thereafter, the process returns (RET) to the main routine.

In the case of Y in S63, the process proceeds to S68, and it is determined whether or not the current peak value c> the previous peak value AMP (b). In the case of Y, the process proceeds to S69. In S69, the previous peak value AMP (b) is rewritten to the current peak value c, and the process proceeds to S70. In S70, it is determined whether or not the current crest value c> the previous amplitude value AMRL1. If Y, the process proceeds to S71, where the current crest value c is input to the previous amplitude value AMRL1.

If the determination of N is made in S68, the process immediately returns to the main routine. Therefore, only when the peak of the new input waveform is large, the amplitude value of the new waveform is registered. (In that case, it is considered that the peak of the overtone is not spread.) When N in S70 and when the process of S71 ends, the process similarly returns to the main routine.

As described above, the following processing is performed on the route according to the example of FIG. MT = 0 ≠ b, RIV = 0, A
MP (1) ← c, AMRL2 ← AMRL1, AMRL1 ← max [AMP (0),
c (whichever is greater)], HNC ← (HNC + 1) = 1, R
IV ← 1, TTR ← (t−TFR), TFR ← t. Accordingly, the difference between the time information from the previous zero-cross point of the same polarity (at STEP 2 → 3) to the current zero-cross point, that is, the cycle information, is obtained in the cycle register TTR. Then, the process returns to the main routine and waits for the next zero cross interrupt.

Next, a description will be given of a case where the vehicle has proceeded to the route shown in S400 to S621. Now, since the waveform number counter HNC is 1, (S
66), execute S400, and proceed from S40 to S42. S42
Then, in the case as shown in FIG. 11, since MT = 0 and b = 0, the result is Y, and the process proceeds to S43. In S43, it is determined whether or not the register RIV = 1. Since the register RIV has already been set to 1 in the route (see S67), the determination in S43 is Y in this case, and the process proceeds to S44.

In S44, it is determined whether or not the register STEP = 4.
In the case of, go to S45. In S45, the peak value c <60H this time
(H indicates a hexadecimal expression) is determined, and since the peak value is large, it becomes Y, and the process proceeds to S46. At S46, it is determined whether or not the amplitude value AMRL2 of the previous time AMRL2−the previous amplitude value AMRL1 ≦ (1/32) × the amplitude value AMRL2 of the previous time, and if Y, the process proceeds to S47, where the relative off counter FOFR is set to 0. You. The relative off processing will be described later. Then, in S48, a cycle calculation is performed. Specifically, (current zero-cross time t-previous zero-cross time data TF)
Is set in the register TOTO as the current cycle information tt. Then, the process proceeds to S49, where the present cycle information tt>
It is determined whether it is the frequency upper limit THLIM (upper limit after the start of sound generation), and in the case of Y, the process proceeds to S50.

The frequency upper limit THLIM of S49 is the upper limit of the allowable range of the frequency at the time of triggering (at the start of sounding) used in S36 of STEP3 (therefore, the minimum period is equivalent to the pitch period two to three semitones above the highest note fret) Is the same as

Next, the following processing is performed in S50. That is, the register RIV is set to 0, the current zero-crossing time t is input as the previous zero-crossing time data TF, the previous peak value AMP (b) is input as the immediately preceding peak value e, and the current peak value c is set as the previous peak value c. It is input to the peak value AMP (b).

Then, after the process of S50, the process proceeds to S51, and in S51, it is determined whether or not the frequency lower limit TLLIM> the present cycle information tt, and Y
In other words, if the current cycle is equal to or less than the lower limit of the pitch-extracted sound range during note-on, the process proceeds to S52.

In this case, the lower frequency limit TLLIM is set, for example, one octave below the open string scale. In other words, the allowable range is wider than the frequency lower limit TTLIM (see S37) of STEP3. By doing so, it becomes possible to cope with a frequency change due to operation of the tremolo arm or the like.

Therefore, the process proceeds to S52 only when the upper limit and lower limit of the frequency fall within the allowable range, and otherwise, the process proceeds to S49, S
Return to the main routine from 51.

Next, in S52, the cycle data TTP is input to the cycle data h extracted two times before, and the current cycle information tt is input to the cycle data TTP extracted last time. Then, in S53, the current peak value c is written to the velocity VEL, and in S531, PP =
Judgment is made as to whether it is 2 or not. Since it is now N, the process proceeds to S54. S
In 54, no change level NCHLV> (previous peak value e
-It is determined whether or not the current crest value is c), and in the case of Y, the process proceeds to S55.

That is, the previous peak value of the same polarity (e = AMP (b))
When the peak value c greatly changes, the difference exceeds NCHLV. In such a case, if the pitch is changed based on the extracted period information, an unnatural pitch It is likely that it will change. Therefore,
If N is determined in S54, the process returns to the main routine without performing the processing in S55 and thereafter.

Next, in the case of Y in S54, the relative off counter FOFR
It is determined whether or not = 0. When the relative off processing described later is performed, the relative off counter FOFR is set to 0.
In such a case, change the pitch (S61
Without performing the process of step S55, and returns N to the main routine in S55. Then, in S55, Y
When the determination is made, the process sequentially proceeds to S56 and S57.

Here, the two-wave ternary coincidence condition is determined. In S56, the current cycle information tt × 2 ⁻⁷ > | current cycle information tt−previous cycle data h | is determined. If Y, the process proceeds to S57, and S57 is performed.
In this case, the current cycle information tt × 2 ⁻⁷ > | current cycle information tt−contents of cycle register TTR | is determined.
Go on. Since PP = 0 now, the judgment of N is made in S571, and then the process proceeds to S58.

That is, in S56, the current cycle information tt (S43
Is determined to be substantially equal to the value of the previous cycle data h (= TTP) (see S52), and in S57, the value of the current cycle information tt substantially matches the cycle TTR overlapping therewith. It is determined whether or not. The limit range is 2 ⁻⁷ × tt, and the value changes depending on the period information. Of course, this may be a fixed value, but better results can be obtained with the technique of this embodiment.

In the next S58, it is determined whether or not this cycle information tt> constant TTU. If Y, the process proceeds to S59, where the current cycle information t
It is determined whether or not t <constant TTW. If Y, the process proceeds to S60.

Steps S58 and S59 are determinations to prevent a sudden change in pitch. In other words, the constant TTU of S58 is now set to 0 in S301 of STEP3, and the constant TTW is similarly set to the value of MAX. When passing through this flow for the first time, Y is always determined in S58 and S59. Thereafter, in S62 described later, the constant TTU
Contains (17/32) tt (periodical information about one octave treble)
Is set, and the constant TTW is similarly set at (31/16) tt in S62.
(Substantially one octave bass period information) is set. Therefore, abrupt octave up (this occurs when you release the fret and put your finger on the center of the string vibration and mute operation, etc.) or octave down (this is when you miss the peak of the waveform, etc.) ), It is unnatural to change the pitch. Branching is performed so as not to change the pitch.

If Y is determined in S58 and S59, then S60
Proceed to. In S60, it is determined whether or not the register STEP = 4. In the case of Y, the process proceeds to S61. In S61, microcomputer MC
The pitch change from P to the sound source SS (based on the current cycle information tt) is performed, the process proceeds to S62, the time constant is changed according to the current cycle information tt, and the constant TTU is (17/32) × this time Is replaced with the periodic information tt, and the constant TTW is (31/16)
× Rewritten to the current cycle information tt.

That is, as will be described later, STEP = 5 is set only when the relative off processing is performed. In that case, the time constant is changed without changing the pitch. The processing of the time constant change corresponds to the time constant conversion control circuit shown in FIG.
This means that the microcomputer MCP sets data based on the value of the current cycle information tt in a register inside the TCC. this is,
As described above.

Then, following the processing of S62, it is judged whether or not the value of the register PP is 2, and since it is N, the process returns to the main routine. Therefore, as described above, the following processing is performed on the route as shown in FIG. That is, HNC = 1, M
T = 0 = b, RIV = 1, FOFR ← 0, tt ← (t−TF), RIV
← 0, TF ← t, e ← AMP (0), AMP (0) ← c, h ← TT
P, TTP ← tt, VEL ← c, and furthermore, the pitch is changed in accordance with tt when the three conditions of TTP ≒ TTR ≒ tt, TTU <tt <TTW, and AMP (0) −c <NCHLV are satisfied. Thereafter, TTU ← (17/32) × tt and TTW ← (31/16) × tt are performed.

Therefore, the pitch is changed with respect to the actual sound source SS in the route, and the route processing is performed in the subsequent zero cross interrupt, and similarly, the route processing is performed in the subsequent zero cross interrupt. In this way, on the route, the period is simply extracted (see S67), on the route, the actual pitch change (see S61), the time constant change process (S62)
Reference).

In step S40 in step 4, after the waveform number counter HNC is counted up in step S66 so that the waveform number counter HNC exceeds 3, the determination of Y is made, and then the process goes to step S41 to detect the relative on condition. This is c-AM
When P (b)> TRLRL and the current amplitude value exceeds the threshold value TRLRL as compared with the previous amplitude value AMRL1, that is, when the same string is picked again after the string operation (tremolo playing method) Such a case occurs in this case. In this case, the process proceeds from S41 to S78 in order to continue the relative on process in S41, and the highest tone fret (for example, 22) is stored in the time constant change register CHTRR of the time constant conversion control circuit TCC.
Set the period CHTIM of the fret). After a while, the fifth
Proceeding to step S06 in the figure, note-off of the currently sounding musical tone is started, and re-sounding is started.

According to the normal performance operation, the process proceeds to S40, S41, S42, and proceeds to the above-described route or route.

Next, with reference to FIG. 12, a description will be given of the processing when the popping performance technique or the like is performed.

As described above, according to the popping playing technique or the like, the polarity of one side of the input waveform signal, in this embodiment, the peak of the negative side becomes α>β> γ as shown in FIG. Therefore, ST
During EP2 processing, PP is set to 1 and CHTRR is
TP (0) is set to c and AMP (0) is set to c.

Then, in STEP3, when PP = 1, TP (0) ≒ TP (1)
Even then, proceed to STEP4 without performing the note-on.

Then, in S400 of STEP4 in FIG. 10, the determination of Y is made, and the process goes to the route. This route is a routine starting from S401. First, in S401, it is determined whether or not b = 1. In the case of the process related to the zero crossing point immediately after the positive peak, judgment such as popping performance cannot be performed. The determination in S401 becomes Y and the process returns to the main routine (RET).

If the process is for the zero crossing point immediately after the negative peak, a judgment of N is made in S401 and the process goes to S402.
In S402, the value of the open string period CHTIO is set in the register CHTRR for period measurement since it is already determined that the current picking is likely to be performed by the popping technique or the like.

Then, in S403, it is judged whether c> AMP (0). If Y is determined in S403, it is determined that the popping style or the like has not been performed, and the process proceeds to S404. The register PP is set to 0 in the sense that the popping style or the like has not been performed. The sound source SS jumps and starts generating a musical tone having a pitch according to the determined cycle from a sound source SS in a normal preselected tone color.

On the other hand, when N judgments are made in S403 (that is,
(When the relationship α>β> γ holds, as shown in Fig. 12)
Proceeds to S405 to instruct the sound source SS to generate a predetermined sound (shown as a PP sound in FIGS. 10 and 12).

The predetermined sound (PP sound) may be a sound that does not allow a specific pitch to be perceived, such as a noise sound, a percussion sound, or a sound that is modulated using noise. This is because the popping technique or the like is a technique of generating a sound by striking a string or pulling the string and then releasing it. In any case, the twelfth
When a scale tone is generated based on the cycle of TP (0) ≒ TP (1) in the figure, the oscillation frequency of the string x ≒ y ≒ z for the fret to be extracted later is different. The cycle must be changed. Therefore, according to this embodiment, the above-described predetermined sound (PP sound) is generated before the generation of the original scale sound, and then the sound is changed to the original scale sound (for example, gradually to the scale sound). Change).

Now, proceeding to S406 following S405, the register PP is set to 2
To indicate that a predetermined sound (PP sound) has been generated, and then sets the flag ONF to 2 and returns to the main routine.

Therefore, in the processing of the main routine subsequent to the next interrupt processing, in step S400, N judgment is made in S400, and the above-described route or route processing is executed.

By the way, in this route, since the register PP = 2 in S531, the process goes to S55 without passing through S54. This is because, according to the popping performance method, the level of the input waveform signal fluctuates greatly, so that the judge ec <N in S54.
In CHLV, it is often N, and if the process returns to the main routine, there is a high possibility that pitch extraction will be delayed. Therefore, when PP = 2, this S5
4 goes to the next S55 by bypassing.

Similarly, in S571, when PP = 2, the judgment of Y is performed, and the process directly proceeds to S60 without going through S58 and S59.

Also, according to the popping playing technique and the like, there is a high possibility that the pitch change suddenly appears as shown in FIG.
Judgment at 9 increases the possibility that pitch extraction will not be possible.
Proceed to S60-S62, and then go from S621 to S622
After setting the register PP to 0 in S622, the process returns to the main routine.

By the way, in the example shown in FIG. 12, when it is detected in STEP 4 that the periods x, y, and z substantially match (see S56 and S57), the pitch is changed to the original fret period for the first time (see S56 and S57). (See S61).

The processing operation of each subsequent flow is as described above, and the route and the route operation are repeatedly executed.

Next, the relative off processing will be described with reference to FIGS. In other words, from the state where you are operating the fret,
When the state shifts to the open string state, the amplitude level of the waveform sharply drops, and when the difference between the peak value AMRL2 of the previous time and the previous peak value AMRL1 exceeds (1/32) AMRL2, S46 to S7
Proceed to 4. Then, the relative off counter FOFR becomes a constant R
From S74 to S75 to count up until it exceeds OFCT
Proceed to. At this time, the process goes from S75 to S48 and performs the processes of S49 to S55. However, since FOFR is not 0, the process returns to the main routine without changing the pitch immediately before entering the relative off process.

When Y is determined in S74, that is, in the example of FIG. 13, when the value of FOFR becomes 3 (ROFCT is 2), S
Go from 74 to S75.

However, if the judgment of Y is at least once in the judgment of S46, the process proceeds from S46 to S47 to reset the FOFR. Therefore, unless the condition of S46 is satisfied continuously for the number of times specified by ROFCT, the relative off processing is not performed. If the value of ROFCT is set to a large value for a string having a high pitch, the relative off processing can be performed for any of the strings after a lapse of a substantially constant time.

Then, when going from S74 to S76, the relative off counter FOFR is reset, the register STEP is set to 5, and the process goes to S77 to instruct the sound source SS to perform note-off. This STEP is 5
In the state of, the pitch extraction process is executed in the same manner as in STEP 4, but since the process proceeds from S60 to S62 without passing through S61,
The pitch is not changed for the sound source SS. However, S6
Time constant change processing is performed according to the cycle extracted in 2.

Then, when the state of STEP is 5, the process of relative on is accepted (S41, S78).
In the main flow of the figure, when it is detected that the vibration level has decreased, STEP becomes 0 in M14, and the process returns to the initial state.

In addition, AMRL1 and AMRL2 used in S46 are made in S64, and the peak having the larger level (one of the maximum peak and the minimum peak) in one cycle is set to this value, and is shown in FIG. In the example, the case where the maximum peak a _k is always larger than the minimum peak b _k−1 , where a _{n + 1} and a _{n + 2} , a _{n + 2} and a _{n + 3} , a _{n + 3} and a Any difference of _{n + 4} exceeds a predetermined value.

At this time, in the route processing, since the minimum peaks b _{n + 1} , b _{n + 2} , b _{n + 3} are extremely reduced, S5
The determination of N is made in 4 and the process returns to the main routine, and the pitch change processing is not performed.

Next, a description will be given of a process performed when harmonics having an octave relationship, that is, octave higher and lower octave sounds are successively detected during pitch extraction.

As described above, in S58, when tt does not exceed the TTU, that is, when tt becomes smaller than the value TTU which is 17/32 times the cycle extracted last time, the process proceeds to S76. In other words, when an octave higher sound is extracted, it is considered that the mute operation is performed by releasing the finger from the designated fret and holding the center of the vibrating string with the finger, and without outputting the octave higher sound. Go from S58 to S76, same as when relative off S7
6, the sound generation of the sound is stopped by the processing of S77.

In S59, when tt does not exceed TTW, that is, when TTW is larger than the value TTW which is 31/16 times the previously extracted cycle, the process returns to the main routine without proceeding to S60.

This state is shown in FIG. Usually, when the waveform is very small near the note-off, the waveform is picked up by crosstalk of the hexa pickup or resonance of the body due to other picking. Then, for example, an input waveform as shown in FIG. 15 may be obtained, and an input waveform one octave lower may be continuously detected.

In such a case, if no processing is performed, a sound immediately below the octave is output, which is extremely unnatural. Therefore, even if Tan _{+ 2} ≒ Ta _{n + 3} ≒ Tb _{n + 2} is detected in S57 and S56, it is necessary to change the pitch because Tan _{+ 3} > Ta _{n + 1} × (31/16). Without returning to the main routine from S59.

Next, a case where a doubled waveform is extracted, that is, a case where zero-cross points having the same polarity continuously arrive will be described. FIG. 16 shows an example in the case of MT = 1. Since the fundamental wave period and the period of the harmonic component are non-integer multiples, the phases of the harmonics are shifted, and the zero crossings of the same polarity are detected. You have to make sure that you do not change the pitch incorrectly.

Therefore, STEP at the time of zero cross written as double in the figure
In the process of 4, the process goes from S42 to S43, and in S43, the determination of Y is made and the process goes to S72. Here, the magnitudes of an _{+ 3} and an _{+ 2} are compared. If an _{+ 3} is greater than an _{+ 2} , a determination of Y is made in S72, and a Set the value of _{n + 3} , and do not change anything if the opposite is true.

By the way, in the case of this double, no extracted time data is used, so that the period information Tan _{+ 3} does not change at all. Also, the pitch is not changed based on the cycle data.

Similarly, FIG. 17 shows an example of the case of waveform double, in which MT = 0.
The state of is shown. At this time as well, the state of double doubling occurs where double doubling is indicated in the figure. At this time, the process goes from S42 to S63, makes a Y determination, and goes to S68. S68
In, and a comparison with a _{n + 2} and a _{n + 3} in the present case, a _{n + 3} is a
Only when it is greater than _{n + 2} , go to S69 and rewrite AMP (1). In this case, the previous amplitude value AMRL1 is compared with the current amplitude information (crest value c) in S70.
Proceeding to 71, the current amplitude information c is set to the previous amplitude value AMRL1.

In this way, even when the waveform is doubled due to the influence of the overtone, the pitch change processing is not performed unless S56 and S57 are satisfied.

As described above, according to the present embodiment, the fact that the popping playing technique or the like has been performed indicates that the peak of one fixed polarity, that is, the negative peak in this embodiment, appears at the start of the string vibration,
In such a case, it is difficult to judge the pitch until the period corresponding to the original fret operation is detected. So that the tone sounds
It becomes possible to prevent an unnatural change in pitch at the start of sounding. Moreover, according to the change of the playing state,
It becomes possible to generate a specific sound.

In the above-described embodiment, the period extraction is performed from the interval of each of the zero cross points next to the maximum peak point and the minimum peak point. However, other methods, such as the time interval between the maximum peak points and the minimum peak point, are used. May be extracted from the data. Further, the circuit configuration can be variously changed in accordance with it.

Further, in the above embodiment, the present invention is applied to an electronic bass guitar (bass guitar synthesizer), but this is due to the fact that the popping technique is often performed. However, the musical instrument to which the present invention can be applied is not limited thereto. Various types of musical instruments or devices that generate a sound signal different from the original signal by performing pitch extraction are applicable.

〔The invention's effect〕

In the present invention, as described in detail above, normally, a musical tone having a pitch specified by the pitch specifying means is instructed to be sounded based on the cycle of the input waveform signal. If it is detected that the wave has a predetermined polarity, and the peak level detecting means detects that the peak level group is sequentially decreasing, it instructs the generation of a predetermined tone different from the tone instructed. Like so
Suitable sound can be generated at the time of a performance operation such as popping performance.

Therefore, when the popping technique or the like is performed, for example, a sound different from the scale sound is generated, and the performance effect is improved. Is gone.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an electronic stringed musical instrument input control device according to the present invention, FIG. 2 is a block diagram showing an example of a pitch extraction digital circuit of FIG. 1, and FIG. 3 is a microcomputer of FIG. FIG. 4 is a flowchart showing a main processing routine of the microcomputer of FIG. 2, and FIG. 5 is a flowchart showing a main processing routine of FIG.
FIG. 10 is a flowchart for explaining the operation of each step of the microcomputer in FIG. 2, and FIGS.
Each figure is a timing chart for explaining the operation of each step. PA: Pitch extraction analog circuit, PD: Pitch extraction digital circuit, MCP: Microcomputer, SS: Sound source, PEDT: Peak detection circuit, ZTS: Zero-cross time acquisition circuit, TCC: Time constant conversion control circuit , PVS …… A peak value capture circuit.

Claims (1)

(57) [Claims] 1. A polarity detecting means for detecting whether or not a first wave of an input waveform signal generated at the time of a string operation has a predetermined polarity; a peak level of the first wave of the input waveform signal; Peak level detecting means for detecting a plurality of peak levels of the same polarity that occur following the wave, and detecting whether or not these peak level groups are sequentially reduced; and a pitch based on a cycle of the input waveform signal. A pitch designation means for designating a tone, and a tone of the pitch designated by the pitch designation means is normally instructed to sound, and the polarity detection means causes the first wave of the input waveform signal to have a predetermined polarity. Is detected, and when it is detected by the peak level detecting means that the peak level group is sequentially decreasing,
An electronic stringed musical instrument comprising: sounding instruction means for instructing sounding of a predetermined sound different from the musical sound for which sounding has been instructed.