JP2015184380A - Electronic stringed instrument, musical sound production method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a pitch of an electronic stringed instrument more efficiently.SOLUTION: An electronic stringed instrument 1 comprises a hex pickup 12 and CPU 41. The hex pickup 12 detects whether any of a plurality of strings 22 stretched on a fingerboard 21 has been picked. The CPU 41 detects vibration pitch of the string 22 that has been picked and detected by the hex pickup 12. According to the detected vibration pitch, the CPU 41 outputs a pitch change command to correct a pitch of a musical sound being produced to a sound source 45 continuously at a time interval set for each of the plurality of strings.

Description

  The present invention relates to an electronic stringed instrument, a musical sound generation method, and a program.

2. Description of the Related Art Conventionally, there is known an electronic stringed instrument that detects a string pressing operation on a fret and generates a musical sound according to a detection result of the string pressing operation when a string stretched on the fret is played.
Such a method requires a switch or a sensor on the fingerboard to recognize the position where the string is pressed, which impairs the appearance of the stringed instrument and cannot cope with changes in pitch after sounding. is there.
In addition, a method of picking up the vibration of a string that has been played with a microphone and recognizing the frequency and amplitude as an electric signal has been proposed (Patent Document 1). In this method, there is no need to provide a switch or sensor on the fingerboard, so the appearance as a stringed instrument is not impaired, and it is possible to respond faithfully to changes in pitch after sounding. Since it takes time until the amplitude is extracted, there is a problem that a slight delay occurs between the string being played and the actual sounding.
Therefore, in recent years, a metal fret and a metal string are used, and the position of the string is detected by detecting the electrical contact between the two, and at the same time as the string of the metal string, the musical tone having the pitch determined by the position of the string is played. A method has been proposed in which sound is generated and then the pitch of the musical sound being generated is corrected with the frequency extracted from the string.
According to such a system, the appearance as a stringed instrument is not impaired, and the sound generation is not delayed.

Japanese Unexamined Patent Publication No. 63-136088

In order to correct the pitch after the tone is generated, a method is used to send a command to the sound source generating the tone to instruct that the pitch should be corrected based on the detected vibration frequency of the string. It is done. If a musical sound that is faithful to the vibration of a string is to be generated, the process of detecting the vibration frequency of the string and sending a command for correcting the pitch while the musical sound is being generated is continuously performed at predetermined intervals. Must be done.
In particular, although the change in the pitch of the musical tone of a stringed instrument is relatively small, this change is due to the fact that the change in pitch is early and unstable and must be corrected to the correct pitch as soon as possible. Sending commands for high correction must also be done frequently at relatively short intervals.
However, sending commands at too short intervals increases the amount of communication data with the sound source and the processing burden on the control system, especially when multiple strings are played simultaneously. There is a risk of disappearing.
On the other hand, the thickness of a plurality of strings is different, and it is known that the vibration frequency decreases as the thickness increases. Therefore, a thin string has a high vibration frequency and a short period, and a change in the vibration frequency is likely to occur. On the other hand, a thick string has a low vibration frequency and thus has a long period, and the vibration frequency does not easily change. Considering this point, it is unreasonable to perform command sending processing for string vibration frequency detection and pitch correction for strings having different thicknesses at the same time interval. That is, if processing is performed at a time interval that matches a thin string, useless processing is performed with a thick string, and if it is matched with a thick string, a change in pitch of a musical tone that occurs with a thin string cannot be faithfully reproduced.

  The present invention has been made in view of such a situation, and an object thereof is to more efficiently perform pitch correction in an electronic stringed instrument.

In order to achieve the above object, an electronic stringed musical instrument according to one aspect of the present invention is provided.
A string detecting means for detecting whether or not any of the plurality of strings stretched on the fingerboard portion is stringed;
String vibration detection means for detecting the vibration pitch of the string whose string was detected by the string detection means;
In response to the vibration pitch detected by the string vibration detection means, a command for correcting the pitch of a musical tone being sounded is continuously applied to the sound source at a time interval set corresponding to each of the plurality of strings. Command output means for outputting;
Have

  According to the present invention, pitch correction in an electronic stringed instrument can be performed more efficiently.

It is a front view which shows the external appearance of an electronic stringed instrument. It is a block diagram which shows the hardware constitutions of an electronic part. It is a schematic diagram which shows the signal control part of a string-pressing sensor. It is a flowchart which shows the main flow performed in an electronic stringed instrument. It is a flowchart which shows an interruption process. It is a flowchart which shows the string state recognition process performed as a subflow in step S3 of a main flow. It is a flowchart which shows the pitch extraction process performed as a subflow in step S9 of a main flow. It is a schematic diagram which shows the vibration waveform of a string. It is a flowchart which shows the command output determination process performed as a subflow in step S14 of a main flow. It is a schematic diagram which shows an example of the unstable time table. It is a schematic diagram which shows an example of the interval table at the time of stability. It is a schematic diagram which shows the concept of operation | movement of an electronic stringed musical instrument. It is a figure which shows an example of the vibration waveform of the string in the pitch of B5.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Outline of electronic stringed instrument 1]
First, an outline of an electronic stringed musical instrument 1 as an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a front view showing an external appearance of the electronic stringed instrument 1. As shown in FIG. 1, the electronic stringed instrument 1 is configured as an electronic guitar, and is roughly divided into a main body 10, a neck 20, and a head 30.

  A bobbin 31 on which one end of a steel string 22 is wound is attached to the head 30, and the neck 20 has a plurality of frets 23 embedded in a fingerboard 21. In the present embodiment, six strings 22 and 22 frets 23 are provided. Each of the six strings 22 is associated with a string number. The thinnest string 22 is the string number “1”, and the string number increases in the order of increasing the thickness of the string 22. Each of the 22 frets 23 is associated with a fret number. The fret 23 closest to the head 30 has the fret number “1”, and the fret number of the arranged fret 23 increases as the distance from the head 30 side increases.

  The main body 10 emits sound from a bridge 16 to which the other end of the string 22 is attached, a normal pickup 11 that detects vibration of the string 22, and a hexapickup 12 that detects vibration of each string 22 independently. A tremolo arm 17 for adding a tremolo effect to the sound, an electronic unit 13 built in the main body 10, a cable 14 for connecting each string 22 and the electronic unit 13, and the type of tone are displayed. A display unit 15 is provided.

FIG. 2 is a block diagram illustrating a hardware configuration of the electronic unit 13. The electronic unit 13 includes a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, a string sensor 44, a sound source 45, a normal pickup 11, a hexa pickup 12, The analog filter 12a, the A / D (analog-digital converter) 12b, the switch 48, the display unit 15, and the I / F (interface) 49 are connected via a bus 50.
Further, the electronic unit 13 includes a DSP (Digital Signal Processor) 46 and a D / A (digital analog converter) 47.

  The CPU 41 executes various processes according to a program recorded in the ROM 42 or a program loaded into the RAM 43 from a storage unit (not shown).

  The RAM 43 appropriately stores data necessary for the CPU 41 to execute various processes. For example, the RAM 43 stores a chord definition table in which the relationship between the chord and the pressed position of the fret 23 is associated. By referring to the chord definition table, if the chord used in the music to be played is found, the CPU 41 can specify the position of the fret 23 pressed by the performer.

  The string-pressing sensor 44 detects what number-of-frets of what-numbered strings are pressed. The string-pressing sensor 44 detects the string-pressing position by detecting an electrical contact between the string 22 and the fret 23.

  The sound source 45 generates, for example, waveform data of a musical tone whose sound is instructed by MIDI (Musical Instrument Digital Interface) data, and an audio signal obtained by D / A conversion of the waveform data via the DSP 46 and D / A 47. Are output to the external sound source 53 to issue instructions for sound generation and mute. The external sound source 53 amplifies an audio signal output from the D / A 47 and outputs it, and a speaker (not shown) that emits a musical sound using the audio signal input from the amplifier circuit. And).

The normal pickup 11 converts the detected vibration of the string 22 into an electric signal and outputs it to the CPU 41.
The hex pickup 12 converts the detected independent vibration of each string 22 into an electric signal and outputs it to the analog filter 12a.
The analog filter 12a allows a set frequency domain component to pass through the vibration waveform of the string detected by the hex pickup 12.
The A / D 12b converts the vibration waveform that has passed through the analog filter 12a from an analog signal to a digital signal, and outputs it to the CPU 41.

The switch 48 outputs input signals from various switches (not shown) provided in the main body 10 to the CPU 41.
The display unit 15 displays the type of timbre to be sounded and the like.

FIG. 3 is a schematic diagram illustrating a signal control unit of the string-pressing sensor 44.
As shown in FIG. 3, in the string sensor 44, 22 selection lines KI0 to KI21 corresponding to the number of frets 23 and 6 signal lines KC0 to KC5 corresponding to the number of strings 22 are arranged in a matrix. It has a configuration.

The signal lines KC0 to KC5 corresponding to the strings 22 are sequentially switched to an active state (here, low level) every predetermined time (for example, 0.1 ms). The selection lines KI0 to KI21 are pulled up to a high level (for example, 5v). When the activated signal lines KC0 to KC5 come into contact with the fret 23 by pushing the strings, the selection lines KI0 to KI21 corresponding to the fret 23 with which the strings are in contact correspond to the states of the signal lines KC0 to KC5. A signal to be read (here, a low level signal) is read out.
That is, the string-pressing sensor 44 switches the signal lines KC0 to KC5 to an active state one by one every predetermined time, reads the state (high level or low level) of the selection lines KI0 to KI21, and for all the frets 23, Detect which position is pressed.

[Main flow]
FIG. 4 is a flowchart showing a main flow executed in the electronic stringed instrument 1 according to the present embodiment.
The main flow shown in FIG. 4 is repeatedly executed by the CPU 41 during the operation of the electronic stringed instrument 1.
When the main flow is started, in step S1, the CPU 41 sets 1 to the string number N to be processed (N = 1), and starts the operation of the timer Ts for sampling the vibration waveform.

In step S2, the CPU 41 determines whether or not sound is being generated.
If it is determined in step S2 that the sound is not being generated (NO), the process proceeds to step S3.
On the other hand, if it is determined in step S2 that the sound is being generated, the process proceeds to step S9.
In step S3, the CPU 41 executes a string state recognition process (see FIG. 6), which is a sub-flow for recognizing the vibration state of the string 22.

In step S4, the CPU 41 determines whether or not the vibration state of the string 22 is in a positive zero cross (zero cross from negative to positive). Specifically, in step S4, the CPU 41 determines whether or not a flag indicating that a positive zero cross is being performed.
In step S4, when it is determined that the vibration state of the string 22 is not in the positive zero cross (NO), that is, it is determined that the flag indicating that the positive zero cross is in the off state, the process proceeds to step S16.
On the other hand, when it is determined in step S4 that the vibration state of the string 22 is in the positive zero cross state (YES), that is, the flag indicating that the positive zero cross is in the on state, the process proceeds to step S5.

In step S5, the CPU 41 determines whether or not the amplitude of the string 22 exceeds a threshold value Th1 for sounding. Specifically, the CPU 41 determines whether or not the absolute value of the positive amplitude value or the negative amplitude value of the string 22 exceeds the threshold value Th1.
If it is determined in step S5 that the amplitude of the string 22 does not exceed the threshold value Th1 for sound generation (NO), the process proceeds to step S6.
On the other hand, if it is determined in step S5 that the amplitude of the string 22 exceeds the threshold value Th1 for sound generation (YES), the process proceeds to step S7.
In step S6, the CPU 41 clears the value of the waveform timer Tc (waveform timer value) for counting the time from the start of sound generation and sets it to zero. The waveform timer value is updated every predetermined time (for example, 1 ms) by an interrupt process (see FIG. 5) executed in parallel with the main flow. The waveform timer Tc has a lower frequency than the timer Ts for sampling the vibration waveform. Therefore, by using the waveform timer Tc, it is possible to realize a timer that synchronizes with the vibration waveform with a lower processing load.

In step S <b> 7, the CPU 41 outputs a command (sound generation command) for starting sound generation to the sound source 45. At this time, the CPU 41 sets the pitch to be generated by each string as the pitch corresponding to the pressed position of the fret 23, and sets the velocity to be generated as the absolute value of the positive amplitude value or the absolute value of the negative amplitude value of the string 22. Among them, a sound generation command is output as a velocity corresponding to a value exceeding the threshold Th1. The velocity to be sounded may be the absolute value of the positive amplitude value of the string 22 or the average value of the absolute values of the negative amplitude value.
In step S8, the CPU 41 sets the waveform timer value to 1.

In step S9, the CPU 41 executes a pitch extraction process (see FIG. 7), which is a sub-flow for extracting the pitch in the vibration waveform of the string 22.
In step S10, the CPU 41 determines whether or not the vibration state of the string 22 is in the positive zero cross state (that is, whether or not the flag indicating that the positive zero cross is in is on).
If it is determined in step S10 that the vibration state of the string 22 is in the positive zero cross state (YES), that is, it is determined that the flag indicating that the positive zero cross is in the on state, the process proceeds to step S11.
On the other hand, if it is determined in step S10 that the vibration state of the string 22 is not during the positive zero cross (NO), that is, it is determined that the flag indicating that the positive zero cross is in the on state, the process proceeds to step S16.
In step S11, the CPU 41 determines whether or not the amplitude of the string 22 exceeds a threshold value Th2 for performing pitch extraction. Specifically, the CPU 41 determines whether or not the absolute value of the positive amplitude value or the negative amplitude value of the string 22 exceeds the threshold value Th2.
In the present embodiment, the threshold value Th2 of the amplitude of the string 22 for performing pitch extraction is assumed to be the same as the threshold value Th1 of the amplitude of the string 22 for generating sound. However, the threshold value Th2 of the amplitude of the string 22 for performing pitch extraction may be different from the threshold value Th1 of the amplitude of the string 22 for performing sound generation.

If it is determined in step S11 that the amplitude of the string 22 exceeds the threshold Th2 for pitch extraction (YES), the process proceeds to step S12.
On the other hand, if it is determined in step S11 that the amplitude of the string 22 does not exceed the threshold Th2 for pitch extraction (NO), the process proceeds to step S6.
In step S12, the CPU 41 calculates the pitch of the vibration of the string 22 by subtracting the zero cross timer value in the previous positive zero cross from the value of the timer Ts in the current positive zero cross (zero cross timer value).
In step S13, the CPU 41 sets the zero cross timer value at the current positive zero cross to the zero cross timer value at the previous positive zero cross.

In step S14, the CPU 41 executes a command output determination process (see FIG. 9), which is a sub-flow for determining whether or not to permit command output, to output a command for correcting the pitch. Judgment is made. As a result of executing the command output determination process, a branch is made when it is determined that command transmission is permitted and a command is output, and when it is determined that command transmission is not permitted and a command is not output.
If it is determined in step S14 that no command is output (NO), the process proceeds to step S16.
On the other hand, if it is determined in step S14 that a command is to be output (YES), the process proceeds to step S15.

In step S15, the CPU 41 outputs a command (pitch change command) for correcting the pitch to the sound source 45 according to the pitch calculated in step S12. At this time, the CPU 41 sets the pitch to be changed for each string as the pitch corresponding to the calculated pitch, and sets the velocity to be corrected to the absolute value of the positive amplitude value of the string 22 or the absolute value of the negative amplitude value. Among them, a pitch change command is output as a velocity corresponding to a value exceeding the threshold Th2. The velocity to be changed may be the absolute value of the positive amplitude value of the string 22 or the average value of the absolute values of the negative amplitude value.
In step S16, the CPU 41 increments the string number N by 1 (N = N + 1).

In step S <b> 17, the CPU 41 determines whether or not the string number N is greater than 6.
If it is determined in step S17 that the string number N is greater than 6 (YES), the process proceeds to step S18.
On the other hand, if it is determined in step S17 that the string number N is 6 or less (NO), the process proceeds to step S2.
In step S18, the CPU 41 sets 1 to the string number N to be processed (N = 1).
After step S18, the process proceeds to step S2.

[Interrupt processing]
Next, interrupt processing will be described.
FIG. 5 is a flowchart showing interrupt processing.
The interrupt process is executed by the CPU 41 every predetermined time (for example, 1 ms) in parallel with the main flow.
When the interrupt process is started, in step S101, the CPU 41 determines whether or not the waveform timer value is zero.

If it is determined in step S101 that the waveform timer value is zero (YES), the interrupt process ends.
On the other hand, if it is determined in step S101 that the waveform timer value is not zero (NO), that is, is 1 or more, the process proceeds to step S102.
In step S102, the CPU 41 increments the waveform timer value by one.
After step S102, the interrupt process ends.

[String state recognition processing]
Next, the string state recognition process will be described.
FIG. 6 is a flowchart showing the string state recognition process executed as a subflow in step S3 of the main flow.
When the string state recognition process is started, in step S201, the CPU 41 applies a scan pulse for activating the string 22 with the string number N.
In step S202, the CPU 41 obtains fret information indicating which fret 23 the string 22 with the string number N is in contact with. At this time, the fret information is acquired from the output signal of the string-pressing sensor 44.

In step S203, the CPU 41 obtains the amplitude of the string 22 with the string number N. At this time, the amplitude of the string 22 is acquired from the output signal of the A / D 12b.
In step S204, the CPU 41 turns off the flag indicating that the positive zero cross is being performed.
In step S205, the CPU 41 determines whether or not the amplitude value acquired this time is zero or positive.
If it is determined in step S205 that the amplitude value acquired this time is zero or not positive (NO), the process proceeds to step S206.
On the other hand, when it is determined in step S205 that the amplitude value acquired this time is zero or positive (YES), the process proceeds to step S209.

In step S206, the CPU 41 determines whether or not the previously acquired amplitude value is zero or positive.
If it is determined in step S206 that the previously acquired amplitude value is zero or not positive (NO), the process proceeds to step S207.
On the other hand, if it is determined in step S206 that the previously acquired amplitude value is zero or positive (YES), the process returns to the main flow.

In step S207, the CPU 41 determines whether or not the current amplitude value is larger in absolute value than the maximum negative amplitude value acquired so far.
If it is determined in step S207 that the current amplitude value is larger in absolute value (YES) than the maximum value of the negative amplitude values acquired so far, the process proceeds to step S208.
On the other hand, if it is determined in step S207 that the absolute value of the current amplitude value is not larger than the maximum negative amplitude value acquired so far (NO), the process returns to the main flow.
In step S208, the CPU 41 sets the current amplitude value as the maximum value of the negative amplitude value.
After step S208, the process returns to the main flow.

In step S209, the CPU 41 determines whether or not the previous amplitude value is zero or positive.
If it is determined in step S209 that the previous amplitude value is zero or not positive (NO), the process proceeds to step S210.
On the other hand, if it is determined in step S209 that the previous amplitude value is zero or positive (YES), the process proceeds to step S211.
In step S210, the CPU 41 turns on a flag indicating that a positive zero cross is being performed.
After step S210, the process returns to the main flow.

In step S211, the CPU 41 determines whether or not the current amplitude value is larger in absolute value than the maximum positive amplitude value acquired so far.
In step S211, when it is determined that the absolute value of the current amplitude value is larger than the maximum value of the positive amplitude values acquired so far (YES), the process proceeds to step S212.
On the other hand, when it is determined in step S211 that the absolute value of the current amplitude value is not larger than the maximum value of the positive amplitude values acquired up to the previous time (NO), the process returns to the main flow.

[Pitch extraction processing]
Next, the pitch extraction process will be described.
FIG. 7 is a flowchart showing the pitch extraction process executed as a sub-flow in step S9 of the main flow.
FIG. 8 is a schematic diagram showing the vibration waveform of the string 22.
When the pitch extraction process is started, in step S301, the CPU 41 acquires the amplitude of the waveform in the string of the string number N output from the A / D 12b.
In step S302, the CPU 41 turns off the flag indicating that the positive zero cross is being performed.

In step S303, the CPU 41 determines whether or not the amplitude value acquired this time is zero or positive.
If it is determined in step S303 that the amplitude value acquired this time is zero or not positive (NO), the process proceeds to step S304.
On the other hand, if it is determined in step S303 that the amplitude value acquired this time is zero or positive (YES), the process proceeds to step S307.

In step S304, the CPU 41 determines whether or not the previously acquired amplitude value is zero or positive.
If it is determined in step S304 that the previously acquired amplitude value is zero or not positive (NO), the process proceeds to step S305.
On the other hand, if it is determined in step S304 that the previously acquired amplitude value is zero or positive (YES), the process returns to the main flow.
In step S305, the CPU 41 determines whether or not the current amplitude value is larger in absolute value than the maximum negative amplitude value acquired so far.
If it is determined in step S305 that the current amplitude value has a larger absolute value (YES) than the maximum negative amplitude value acquired up to the previous time (YES), the process proceeds to step S306.
On the other hand, in step S305, when it is determined that the absolute value of the current amplitude value is not larger than the maximum value of the negative amplitude values acquired so far (NO), the process returns to the main flow.

In step S306, the CPU 41 sets the current amplitude value as the peak value of the negative amplitude value.
After step S306, the process returns to the main flow.
In step S307, the CPU 41 determines whether or not the previous amplitude value is zero or positive.
If it is determined in step S307 that the previous amplitude value is zero or not positive (NO), the process proceeds to step S308.
On the other hand, if it is determined in step S307 that the previous amplitude value is zero or positive (YES), the process proceeds to step S310.
In step S308, the CPU 41 sets the current timer Ts value as the zero cross timer value.
In step S309, the CPU 41 turns on a flag indicating that a positive zero cross is being performed.
After step S309, the process returns to the main flow.

In step S310, the CPU 41 determines whether or not the current amplitude value is larger in absolute value than the maximum value of the positive amplitude values acquired so far.
If it is determined in step S310 that the current amplitude value is larger in absolute value (YES) than the maximum value of the positive amplitude values acquired so far, the process proceeds to step S311.
On the other hand, in step S310, if it is determined that the absolute value of the current amplitude value is not larger than the maximum value of the positive amplitude values acquired up to the previous time (NO), the process returns to the main flow.
By such processing, a negative peak value and a positive peak value are detected in the vibration waveform shown in FIG. 8, and a zero cross timer value Tb at a positive zero cross point sandwiched between these is detected. Then, the pitch is calculated from the difference (T−Tb) between the zero cross timer value Tb and the zero cross timer value T of the positive zero cross point detected next.

[Command output judgment processing]
Next, command output determination processing will be described.
FIG. 9 is a flowchart showing command output determination processing executed as a subflow in step S14 of the main flow.
In the command output determination process, a table (hereinafter referred to as “unstable time table”) that indicates the elapsed time (unstable time It) for determining that the string vibration is unstable is used for each string and each fret. It is done. In the command output determination process, after the string vibration is stabilized, a time interval (stable interval time St) for outputting the pitch change command is indicated for each string and each fret (hereinafter referred to as “stable interval table”). .) Is used.

FIG. 10 is a schematic diagram illustrating an example of the unstable time table.
As shown in FIG. 10, in the unstable time table, an unstable time It for determining that the string vibration corresponding to the pressed fret is unstable for each of the strings 22 of the string numbers 1 to 6 is set. Yes. The unstable time It is set based on an experimental value or a theoretical value obtained by actually measuring the vibration of the string in the electronic stringed instrument 1.
For example, when the string 22 with the string number 4 is pressed with the fret numbers 1 to 5, the waveform timer value = 7 is the unstable time It, and when the string is pressed with the fret numbers 6 to 11, the waveform timer value = Up to 6 is the unstable time It. Similarly, when the string is pressed with the fret numbers 12 to 17, the waveform timer value = 5 is the unstable time It, and when the string is pressed with the fret numbers 18 to 22, the waveform timer value = 4 is the unstable time It. It is.

In the unstable time table shown in FIG. 10, the unstable time It becomes longer as the string becomes thinner and as the string is pushed by the lower fret. This is because it takes a longer time for the vibration of the string to become stable as the string becomes thinner and the string is pushed by the lower fret.
The fret groups shown in FIG. 10 are merely examples, and can be divided into a smaller number of groups, or can be divided into a larger number of groups, including the case where each fret is set.

FIG. 11 is a schematic diagram illustrating an example of a stable interval table.
As shown in FIG. 11, in the stable interval table, for each of the strings 22 of the string numbers 1 to 6, the stable interval time St for outputting the pitch change command after the string vibration corresponding to the pressed fret is stabilized. Is set.
For example, when the string 22 with the string number 4 is pressed with the fret numbers 1 to 5, the time interval of the waveform timer value = 40 is the stable interval time St, and the fret numbers 6 to 11 and the fret numbers 12 to 17 When the string is pressed, the time interval of waveform timer value = 30 is the stable interval time St. Similarly, when the string is pressed with the fret numbers 18 to 22, the time interval of the waveform timer value = 40 is the stable interval time St.

In the stable interval table shown in FIG. 11, the stable interval time St becomes shorter as the string becomes thinner and as the string is pushed by the high-frequency side fret. This is because the narrower the string and the more the string is pressed by the high-pitched fret, the higher the sound that is sounded and the higher the frequency of outputting the pitch change command.
Note that the fret groups shown in FIG. 11 are merely examples, and can be divided into a smaller number of groups, or can be divided into a larger number of groups, including the case of setting for each fret.

In FIG. 9, when the command output determination process is started, in step S401, the CPU 41 determines whether or not the waveform timer value has passed the unstable time It set for the target string 22. Do. Specifically, in step S401, the CPU 41 determines whether or not the waveform timer value of the string 22 that has been struck has passed the unstable time It set for the string 22 in FIG. Do.
If it is determined in step S401 that the waveform timer value has passed the unstable time It set for the target string 22 (YES), the process proceeds to step S402.
On the other hand, if it is determined in step S401 that the waveform timer value has not passed the unstable time It set for the target string 22 (NO), the process proceeds to step S404.

In step S402, the CPU 41 subtracts the previous command output time from the current waveform timer value, and calculates the elapsed time from the previous command output.
In step S403, the CPU 41 determines whether or not the elapsed time from the previous command output is equal to or less than the stable interval time St set for the target string 22.
If it is determined in step S403 that the elapsed time from the previous command output is equal to or less than the stable interval time St set for the target string 22 (YES), the process returns to the main flow.
On the other hand, if it is determined in step S403 that the elapsed time from the previous command output is not less than or equal to the stable time interval St set for the target string 22 (NO), the process proceeds to step S404.

In step S404, the CPU 41 sets a state in which command transmission is permitted.
In step S405, the CPU 41 sets the current waveform timer value to the previous command output time.
After step S405, the process returns to the main flow.

FIG. 12 is a schematic diagram showing the concept of operation of the electronic stringed instrument 1.
In FIG. 12, the vibration waveform of the string shaped by the filter processing and the timing at which the pitch change command is transmitted are shown in association with the waveform timer value.
As shown in FIG. 12, as a result of executing the above-described process, in the electronic stringed instrument 1, when a string is played and a sound generation command is output, the unstable time It set for each string has elapsed. Until then, a pitch change command is output every time a positive zero cross point is detected (that is, every cycle).

Then, after the unstable time It set for the string that has been played has elapsed, the pitch change command is issued each time a positive zero cross point is detected after the stable time interval St set for that string has elapsed. Is output.
For this reason, a pitch change command for quickly correcting the pitch with respect to the change in pitch is output, and when the change in pitch is small, the frequency with which the pitch change command is output is reduced.
The pitch change command is output at a frequency according to each string and the pressed position.
Therefore, the pitch of the electronic stringed instrument 1 can be corrected more efficiently.

FIG. 13 is a diagram illustrating an example of the vibration waveform of the string at the pitch of B5.
In the case of the vibration waveform shown in FIG. 13, the period of the waveform is about 1.01 ms.
Here, for example, a command in MIDI requires about 1 ms for transmission of one command. Therefore, if a pitch change command is output every cycle, there is a high possibility that the amount of communication data will be saturated by transmission of the command. In particular, when a plurality of strings are played, there is a higher possibility that the amount of communication data will be saturated due to the transmission of commands.
On the other hand, in the case of the electronic stringed instrument 1 in the present embodiment, the frequency of outputting the pitch change command decreases after the vibration of the string is stabilized, so that saturation of the communication data amount can be suppressed.

[Modification 1]
In the above-described embodiment, the unstable period and the stable period are identified depending on whether or not the count value of the waveform timer Tc has passed the unstable time It, and the frequency of outputting the pitch change command is changed. The string vibration stability may be determined based on the pitch extraction result, and the frequency of the pitch change command may be changed. That is, it may be determined that the vibration of the string is stable when the change in pitch acquired by pitch extraction is equal to or less than the threshold value Pth1 (first threshold value) for determining the stability of the pitch.
This makes it possible to determine the stability of string vibration more quickly and more accurately in response to the direct state of the string vibration waveform.

[Modification 2]
In the above-described embodiment, it may be determined from the pitch extraction result whether or not the pitch after sounding has been changed by a choking technique or the like, and the frequency at which the pitch change command is output may be changed. In other words, when it is determined that the pitch has changed by the threshold value Pth2 (second threshold) or more after the unstable time It has elapsed, the CPU 41 increases the frequency of outputting the pitch change command (time interval). Can be controlled). At this time, if it is determined that the pitch has changed by the threshold value Pth2 or more, a pitch change command may be output immediately.
This makes it possible to correct the pitch more appropriately in accordance with the performance method of the performer.

[Modification 3]
In the above-described embodiment, the unstable time It set in the unstable time table shown in FIG. 10 may be changed according to the strength of the string. That is, when the amplitude of the detected vibration waveform of the string is large, the unstable time It is increased, and when the amplitude of the detected guidance waveform of the string is small, the unstable time It is changed to be smaller. May be. In this case, the unstable time It set in the unstable time table shown in FIG. 1 can be changed by multiplying by a coefficient corresponding to the magnitude of the amplitude of the vibration waveform of the string. Alternatively, a plurality of unstable time tables corresponding to the amplitude of the string vibration waveform are prepared, and one of the unstable time tables is set according to the detected amplitude of the vibration waveform of the string. It is good also as selecting and using.
As a result, when a string is strongly played, it is possible to set a more appropriate unstable time It in consideration of the phenomenon that the vibration of the string is difficult to stabilize.

The electronic stringed musical instrument 1 configured as described above includes a hex pickup 12 and a CPU 41.
The hex pickup 12 detects whether any of the plurality of strings 22 stretched on the fingerboard 21 is played.
The CPU 41 detects the vibration pitch of the string 22 from which the string is detected by the hexa pickup 12.
In addition, the CPU 41 continuously issues a pitch change command for correcting the pitch of the tone being generated according to the detected vibration pitch at a time interval set corresponding to each of the plurality of strings. Output to.
Thereby, a pitch change command is output at a frequency corresponding to each string.
Therefore, the pitch of the electronic stringed instrument 1 can be corrected more efficiently.

The electronic stringed instrument 1 includes a string-pressing sensor 44.
The string-pressing sensor 44 is provided in each of the plurality of frets 23 on the fingerboard 21 and detects a contact state between the plurality of strings 22 stretched on the fingerboard 21 and the plurality of frets 23.
The CPU 41 determines the pitch change command corresponding to the contact state with the fret 23 detected by the string sensor 44 based on the output time interval of the pitch change command set for each string 22 corresponding to the position of the fret 23. Output.
Thereby, a pitch change command is output at a frequency corresponding to the string pressing position of each string.
Therefore, the pitch of the electronic stringed instrument 1 can be corrected more efficiently.

The CPU 41 determines whether or not the detected change in the vibration pitch of the string 22 is in a predetermined state or less.
Further, when the CPU 41 determines that the change in the vibration pitch of the string 22 is in a predetermined state or less, the CPU 41 changes the pitch compared to the case in which the change in the vibration pitch of the string 22 is determined not to be in a predetermined state or less. Increase the time interval for command output.
As a result, a pitch change command for quickly correcting the pitch with respect to a change in pitch is output, and when the change in pitch is small, the frequency with which the pitch change command is output is reduced.
Therefore, the pitch of the electronic stringed instrument 1 can be corrected more efficiently.

The CPU 41 has a waveform timer Tc that counts the time from the start of sound generation.
Further, the CPU 41 controls the output time interval of the pitch change command by the count value of the waveform timer Tc.
Thus, the output interval of the pitch change command can be easily controlled using the counted value of the waveform timer Tc.

  In addition, this invention is not limited to the above-mentioned embodiment, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.

  For example, in the above-described embodiment, the unstable time set in the unstable time table in FIG. 10 is an example, and the present invention is not limited to this. That is, if the unstable time It becomes longer as the string becomes thinner or the string is pressed by the lower fret, the unstable time It set in the unstable time table according to the specifications of the electronic stringed instrument 1 and the like. Can be variously changed.

  Similarly, in the above-described embodiment, the stable interval time St set in the stable interval table in FIG. 11 is an example, and is not limited thereto. That is, if the stable interval time St becomes shorter as the string becomes thinner or the string is pressed by the high-frequency fret, the stable interval set in the stable interval table according to the specifications of the electronic stringed instrument 1 and the like. The time St can be changed variously.

  In the above-described embodiment, the electronic guitar is described as an example of the electronic stringed instrument to which the present invention is applied. However, the electronic stringed instrument is not limited to this, and any electronic stringed instrument other than the electronic guitar can be used as long as the string is operated. Can also be configured.

  The series of processes described above can be executed by hardware or can be executed by software.

When a series of processing is executed by software, a program constituting the software is installed on a computer or the like from a network or a recording medium.
The computer may be a computer incorporated in dedicated hardware. The computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

  The recording medium including such a program is configured by a recording medium provided to the user in a state of being incorporated in advance in the apparatus main body and distributed separately from the apparatus main body in order to provide the user with the program. The recording medium is composed of, for example, a magnetic disk (including a floppy disk), an optical disk, a magneto-optical disk, or the like. The optical disc is composed of, for example, a CD-ROM (Compact Disk-Read Only Memory), a DVD (Digital Versatile Disc), a Blu-ray (registered trademark) Disc (Blu-ray Disc), and the like. The magneto-optical disk is configured by an MD (Mini-Disk) or the like. Further, the recording medium provided to the user in a state of being pre-installed in the apparatus main body is constituted by the ROM 42 in FIG. 2 in which a program is recorded, for example.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the order, but is not necessarily performed in chronological order, either in parallel or individually. The process to be executed is also included.

  As mentioned above, although several embodiment of this invention was described, these embodiment is only an illustration and does not limit the technical scope of this invention. The present invention can take other various embodiments, and various modifications such as omission and replacement can be made without departing from the gist of the present invention. These embodiments and modifications thereof are included in the scope and gist of the invention described in this specification and the like, and are included in the invention described in the claims and the equivalents thereof.

The invention described in the scope of claims at the beginning of the filing of the present application will be appended.
[Appendix 1]
A string detecting means for detecting whether or not any of the plurality of strings stretched on the fingerboard portion is stringed;
String vibration detection means for detecting the vibration pitch of the string whose string was detected by the string detection means;
In response to the vibration pitch detected by the string vibration detection means, a command for correcting the pitch of a musical tone being sounded is continuously applied to the sound source at a time interval set corresponding to each of the plurality of strings. Command output means for outputting;
Electronic stringed instrument with
[Appendix 2]
A plurality of sensors provided on each of the plurality of frets on the fingerboard unit, and further detecting a contact state between the plurality of strings stretched on the fingerboard unit and the plurality of frets;
The command output means outputs the command according to the contact state with the fret detected by the sensor based on the output time interval of the command set corresponding to the position of the fret for each string. The electronic stringed instrument according to Appendix 1, wherein
[Appendix 3]
Vibration state determination means for determining whether or not a change in the vibration pitch of the string detected by the string vibration detection means is in a predetermined state or less;
The command output means determines that the change in the string vibration pitch is not less than or equal to the predetermined state when the vibration state determination means determines that the change in the string vibration pitch is less than or equal to the predetermined value. The electronic stringed instrument according to appendix 1 or 2, wherein the time interval of the output of the command is increased as compared with the case.
[Appendix 4]
A waveform timer that counts the elapsed time from the start of sound generation
The electronic stringed instrument according to any one of appendices 1 to 3, wherein the command output means controls a time interval of output of the command by a count value of the waveform timer.
[Appendix 5]
A musical sound generating method used for an electronic stringed instrument comprising a string detecting means for detecting whether or not any of a plurality of strings stretched on a fingerboard is played,
The electronic stringed instrument is
Detecting the vibration pitch of the string from which the string was detected by the string detection means,
A musical sound generating method for continuously outputting a command for correcting a pitch of a musical sound being generated according to a detected vibration pitch to a sound source at a time interval set corresponding to each of the plurality of strings. .
[Appendix 6]
In a computer used as an electronic stringed instrument provided with a string detecting means for detecting whether or not any of a plurality of strings stretched on a fingerboard part is stringed,
A string vibration detecting step for detecting a vibration pitch of a string whose string is detected by the string detecting means;
In response to the vibration pitch detected in the string vibration detection step, a command for correcting the pitch of a musical tone being sounded is continuously applied to the sound source at time intervals set corresponding to the plurality of strings. A command output step to output;
A program that executes

  DESCRIPTION OF SYMBOLS 1 ... Electronic string instrument, 10 ... Main body, 11 ... Normal pickup, 12 ... Hexa pickup, 12a ... Analog filter, 12b ... A / D, 13 ... Electronic part, 14 ... Cable, 15 ... Display, 16 ... Bridge, 17 ... Tremolo arm, 20 ... Neck, 21 ... Fingerboard, 22 ... String, 23 ... Fret, 30 ... head, 31 ... pincushion, 41 ... CPU, 42 ... ROM, 43 ... RAM, 44 ... string sensor, 45 ... sound source, 46 ... DSP, 47 ... D / A, 48 ... Switch, 49 ... I / F, 50 ... Bus, 53 ... External sound source, KI0-KI21 ... Select line, KC0-KC5 ... Signal line

Claims (6)

A string detecting means for detecting whether or not any of the plurality of strings stretched on the fingerboard portion is stringed;
String vibration detection means for detecting the vibration pitch of the string whose string was detected by the string detection means;
In response to the vibration pitch detected by the string vibration detection means, a command for correcting the pitch of a musical tone being sounded is continuously applied to the sound source at a time interval set corresponding to each of the plurality of strings. Command output means for outputting;
Electronic stringed instrument with A plurality of sensors provided on each of the plurality of frets on the fingerboard unit, and further detecting a contact state between the plurality of strings stretched on the fingerboard unit and the plurality of frets;
The command output means outputs the command according to the contact state with the fret detected by the sensor based on the output time interval of the command set corresponding to the position of the fret for each string. The electronic stringed instrument of Claim 1 which performs. Vibration state determination means for determining whether or not a change in the vibration pitch of the string detected by the string vibration detection means is in a predetermined state or less;
The command output means determines that the change in the string vibration pitch is not less than or equal to the predetermined state when the vibration state determination means determines that the change in the string vibration pitch is less than or equal to the predetermined value. The electronic stringed instrument according to claim 1, wherein a time interval of output of the command is increased as compared with a case. A waveform timer that counts the elapsed time from the start of sound generation
The electronic stringed instrument according to any one of claims 1 to 3, wherein the command output means controls a time interval of output of the command by a count value of the waveform timer. A musical sound generating method used for an electronic stringed instrument comprising a string detecting means for detecting whether or not any of a plurality of strings stretched on a fingerboard is played,
The electronic stringed instrument is
Detecting the vibration pitch of the string from which the string was detected by the string detection means,
A musical sound generating method for continuously outputting a command for correcting a pitch of a musical sound being generated according to a detected vibration pitch to a sound source at a time interval set corresponding to each of the plurality of strings. . In a computer used as an electronic stringed instrument provided with a string detecting means for detecting whether or not any of a plurality of strings stretched on a fingerboard part is stringed,
A string vibration detecting step for detecting a vibration pitch of a string whose string is detected by the string detecting means;
In response to the vibration pitch detected in the string vibration detection step, a command for correcting the pitch of a musical tone being sounded is continuously applied to the sound source at time intervals set corresponding to the plurality of strings. A command output step to output;
A program that executes

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