JP3534932B2 - Musical tone control device for electronic stringed instruments - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone control device for an electronic string instrument, and more specifically, it extracts pitch (vibration frequency) and amplitude from string vibration and generates a musical tone based on the extracted pitch and amplitude. The present invention relates to a musical tone control device for an electronic stringed instrument that generates instruction information.

[0002]

2. Description of the Related Art Generally, in a conventional electronic string instrument,
The pitch and amplitude are measured from the string waveform signal obtained by the pickup, and the tone generation instruction device is controlled according to the measured values.

However, musical tones generated based only on pitch and amplitude, such as the musical tones generated by the above-described conventional electronic stringed instruments, are less changed than musical tones obtained by acoustic musical instruments and electric musical instruments. It was pointed out that the sound tends to be monotonous.

Therefore, it has been proposed to control a musical sound by using a special operator such as a pedal so as to give a change to a sound to be generated, and it is widely used as an effective musical sound control method even now. There is.

[0005]

However, in the musical tone control method using the special operation element such as the pedal described above, it is necessary to become familiar with the operation method of the special operation element such as the pedal in addition to the ordinary playing method of the stringed instrument. Therefore, there is a problem that it is not necessarily a musical tone control method that is easy to operate for a string instrument player.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a normal stringed instrument without using a special operating element such as a pedal. An object of the present invention is to provide a musical tone control device for an electronic stringed instrument that can change the sound to be produced by using only the playing method.

[0007]

In order to achieve the above object, a tone control device for an electronic string instrument according to the present invention, in a stringed instrument such as a guitar, changes the tone color of a tone produced in accordance with the string position. In view of the fact that it is known to the player that the tone color is changed according to the change in the string position as a normal string instrument playing method, the waveform signal obtained by detecting the string vibration is It was made paying attention to the point that it has characteristics due to the difference in playing style, and by controlling the musical tone generating means with a value that has been subjected to predetermined processing based on the waveform signal obtained by detecting the string vibration, It is possible to perform natural musical tone control more in line with the performer's intention.

That is, in the musical tone control apparatus for an electronic musical instrument according to the present invention, the time interval from the first type peak of the waveform signal obtained by detecting the string vibration to the second peak next to the first type peak is measured. Based on the time interval measured by the peak time measuring means, the musical tone generating means for generating a musical tone corresponding to the waveform signal, and the peak interval measuring means,
Mixing balance of tone colors of predetermined two types of tone sounds generated by the tone generating means, localization of tone color of a predetermined tone generated by the tone generating means, or attack level of tone sounds generated by the tone generating means. It has a control means for controlling the above.

The waveform signal obtained by detecting the string vibration is
The time interval from the peak of the first type to the peak of the second type changes depending on the plucked position of the string. The change of the time interval measured by the peak interval measuring means is the same as the change of the plucking position, and the control means controls the musical sound generating means based on this time interval. It is possible to change the generated musical sound by the usual playing method of changing the position.

Therefore, according to the musical tone control apparatus for an electronic stringed instrument of the present invention, the musical tone control apparatus for an ordinary electronic stringed instrument can be played without significantly changing the structure for measuring the peak interval which is essential for pitch detection in the musical tone control apparatus for an ordinary electronic stringed instrument. It is possible to perform musical tone control according to the string position.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an electronic stringed instrument equipped with a musical tone control device for an electronic stringed instrument according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the overall configuration of an embodiment of an electronic string instrument according to the present invention. In this electronic string instrument, a divided pickup 10 is mounted on a string instrument such as a guitar. The central processing unit (CPU) is arranged in the vicinity of the installed string 20 and based on the string waveform signal Ws obtained by the divided pickup 10.
The tone generation device 14 is controlled by the processing of 12 to generate a tone.

In the description of this embodiment,
A case where a guitar in which six strings 20 are stretched is used as a string instrument will be described.

That is, the divided pickup 10 is
It is arranged in the vicinity of the bridge 18 between the nut 16 and the bridge 18 of the guitar in which the six strings 20 are stretched between them. When the strings 20 are struck, the string vibration of each string 20 is generated. It detects and converts the detected string vibration into a string waveform signal Ws and outputs it.

The string waveform signal Ws output from the divided pickup 10 is input to a low pass filter 22 and, after removing unnecessary harmonic components by the low pass filter 22, a positive peak pulse generator 24 and a negative peak pulse generator. 26 and the envelope detector 28.

The low-pass filter 22, the positive peak pulse generator 24, and the negative peak pulse generator 26.
Is provided for each string of the string 20,
Therefore, in this embodiment, six low pass filters 22, a positive peak pulse generator 24, and a negative peak pulse generator 26 are provided corresponding to the six strings 20.

Here, the positive peak pulse generator 24 and the negative peak pulse generator 26 are well-known devices in the electronic stringed instrument, and the pulse signal Pa synchronized with the positive peak (described later) of the string waveform signal Ws, respectively. And a pulse signal Pb synchronized with a negative peak (described later) are output, and the output pulse signals Pa and Pb are input to the peak interval measuring device 30.

The peak interval measuring device 30 measures and outputs the pulse interval of the pulse signal Pa, the pulse interval of the pulse signal Pb, and the interval between the pulse of the pulse signal Pa and the pulse of the pulse signal Pb for each string. Further, the envelope detection device 28 outputs the envelope of the string waveform signal Ws for each string, and the CPU 12 generates a musical tone from the output of the peak interval measurement device 30 and the output of the envelope detection device 28. The instruction information is generated and output to the musical sound generating device 14.

The musical tone generator 14 generates a digital musical tone signal based on the musical tone generation instruction information inputted from the CPU 12 through a low pass filter, and the digital musical tone signal thus generated is D / A (digital / analog) converter. 32 is converted into an analog musical tone signal by the audio device 34.
It is designed to be emitted into the space as a musical sound that can be heard via.

Reference numeral 36 is a read only memory (ROM) 36 in which a program for executing various processes of the CPU 12, which will be described later with reference to the flowchart, is stored. Reference numeral 38 is provided by the CPU 12. A random access memory (RAM) as a working area in which registers necessary for execution of various processes based on a program are set. For example, the outputs of the envelope detection device 28 and the peak interval measurement device 30 are temporarily stored. Alternatively, it stores the control parameters of the tone generator 14.

Here, what kind of waveform the divided pickup 10 outputs when the string 20 is struck will be described with reference to the model case shown in FIG.

First, as shown in FIG. 2A, the string 20 (open string) which is not pressed is located near the neck (hereinafter, simply referred to as "neck side (nut 16 side)"). 2 (a-1) in FIG. 2A), when the wave motion of the string 20 propagates in both the bridge 18 side and the nut 16 side and reaches the bridge 18 and the nut 16. Each is reflected and returns as a wave of opposite phase. Then, when the waves in these two directions make exactly one round trip on the string 20, the wave returns to the same wave state as at the moment of striking,
It becomes one cycle of the waveform.

When the divided wave is detected by the divided pickup 10, the wave is detected by the divided pickup 1.
When it is right above 0, the rate of change of the waveform of the string waveform signal Ws becomes maximum. When the wave has a positive phase, the rate of change becomes maximum in the positive direction, and when the wave has a reverse phase, the rate of change becomes maximum in the negative direction.

Regarding each of the wave traveling on the bridge 18 side and the wave traveling on the nut 16 side,
FIG. 2A shows (a-2) and (a-3) in which the phase change is represented on the time (t) axis.

Further, the string waveform signal Ws output from the divided pickup 10 is generated by the wave motion in both directions of the wave motion advancing to the bridge 18 side and the wave motion advancing to the nut 16 side.
Waveform becomes as shown in (a-4) of FIG.

That is, (a-2) in FIG. 2 (a) shows a change in the phase of the wave traveling to the bridge 18 side,
First, when the positive-phase wave passes directly above the divided pickup 10, the rate of change of the waveform of the string waveform signal Ws becomes maximum in the positive direction (see arrow A). Then, when the wave passing directly above the divided pickup 10 reaches the bridge 18, the wave is reflected by the bridge 18 and returned as an opposite phase wave. When the wave of the opposite phase passes directly above the divided pickup 10, the rate of change of the waveform of the string waveform signal Ws becomes maximum in the negative direction (arrow B).
reference). Further, the wave of the opposite phase that has passed directly above the divided pickup 10 reaches the nut 16 and the nut 1
The wave is reflected by 6 to be returned as a positive-phase wave, reaches the plucked position, and becomes one cycle of the waveform.

On the other hand, (a-3) of FIG. 2 (a) shows a change in the phase of the wave motion propagating to the nut 16 side. First, when the positive phase wave motion reaches the nut 16, the nut 16 causes It is reflected and returned as an antiphase wave. When the wave of the opposite phase passes right above the divided pickup 10, the rate of change of the waveform of the string waveform signal Ws becomes maximum in the negative direction (see arrow C). When the wave passing directly above the divided pickup 10 reaches the bridge 18, the wave is reflected by the bridge 18 and returned as a positive phase wave, and when passing directly above the divided pickup 10, the string The rate of change of the waveform of the waveform signal Ws becomes maximum in the positive direction (see arrow D). Further, this positive-phase wave reaches the plucked position, and becomes one cycle of the waveform.

In the present specification, "positive peak" is used.
Means a moment α at which the rate of change of the waveform of the string waveform signal Ws becomes 0 on the way from the maximum in the positive direction to the maximum in the negative direction, and the “negative peak” means the string. It means an instant β at which the rate of change of the waveform of the waveform signal Ws becomes 0 during the change from the maximum in the negative direction to the maximum in the positive direction.

Next, as shown in FIG. 2B, the string 20 (open string) which is not pressed is located near the bridge 18 (hereinafter, simply referred to as "bridge 18 side").
When the string is struck with (see (b-1) of FIG. 2 (b)),
Since the distance from the string position to the bridge 18 is shorter than that in the case of FIG. 2A, the time from the moment of stringing until the wave traveling to the bridge 18 reaches the divided pickup 10 is shown in FIG. 2) as shown in (b-2) of FIG.
It becomes shorter than (a-2) in (a), and as a result,
As shown in (b-4) of FIG. 2B, the time until the waveform of the string waveform signal Ws reaches the positive peak is shown in FIG.
Compared to (a-4) in (a), it is closer to the moment of plucking.

On the other hand, since the distance from the plucking position to the nut 16 is longer than in the case of FIG. 2A, the time from the moment of plucking until the wave traveling to the nut 16 side reaches the divided pickup 10. Is (b- in FIG. 2B).
3), it becomes longer than that of (a-3) in FIG. 2 (a), and as a result, as shown in (b-4) of FIG. 2 (b), the waveform of the string waveform signal Ws The time until reaching the negative peak is far from the moment of plucking as compared with (a-4) in FIG.

However, since both FIG. 2 (a) and FIG. 2 (b) are performed with open strings,
Since the entire lengths (effective lengths) of the vibrating parts of the strings 20 are equal, the cycle of the waveform of the string waveform signal Ws becomes equal. Therefore, comparing (a-4) of FIG. 2 (a) and (b-4) of FIG. 2 (b) with the positive peak of the waveform of the string waveform signal Ws as a reference,
Regarding the negative peak of the waveform of the string waveform signal Ws, FIG.
It can be seen that (b-4) in FIG. 2 (b) is located behind the (a-4) in (a).

Further, as shown in FIG. 2 (c), when the string 20 in which the fifth fret is pressed by a finger is struck at the same position as in FIG. 2 (a) ((c in FIG. 2 (c)). -1)), the phase change of the wave traveling to the bridge 18 side and the wave traveling to the nut 16 side based on the same principle as described in FIG. 2C shows (c-2) and (c-3) in FIG. 2C, and the waveform of the string waveform signal Ws output from the divided pickup 10 is (c-) in FIG. 2C.
As shown in 4).

2 (a) (b) (c), the positive peak of the waveform of the string waveform signal Ws is the bridge 18 in any case with reference to the time at the moment of plucking. The time when the wave traveling to the side reaches the bridge 18, and the negative peak of the waveform of the string waveform signal Ws reaches the bridge 18 when the wave traveling to the nut 16 side is reflected at the nut 16 or the pressed string position. Matches

From the above, the time from the negative peak to the positive peak of the waveform of the string waveform signal Ws is uniquely determined by the distance from the plucked position to the bridge 18 regardless of the effective length of the string 20. is there.

Next, referring to FIG. 3 showing a state in which the waveform in the model case shown in FIG. 2 is actually observed,
The measurement of the time interval from the negative peak to the positive peak of the waveform of the string waveform signal Ws will be described.

FIG. 3 (a) shows a case corresponding to FIG. 2 (a). In the case where the unpressed string 20 (open string) is struck by the neck side (nut 16 side). , The relationship between the string waveform signal Ws immediately after the plucked string obtained by the divided pickup 10, the output signal Pa of the positive peak pulse generator 24, and the output signal Pb of the negative peak pulse generator 26 is shown.

Let Ta be the time from the fall of the output signal Pa to the rise of the output signal Pb (the positive peak-negative peak interval), and the time from the rise of the output signal Pb to the fall of the output signal Pa (negative). The peak-positive peak interval) is Tb, and "Ta + Tb = T (positive peak-positive peak interval)".

FIG. 3 (b) shows a case corresponding to FIG. 2 (b), in which a string 20 (open string) which is not pressed is tuned by the bridge 18 side. The string waveform signal Ws immediately after the plucked string obtained by the dead pickup 10 and the output signal Pa of the positive peak pulse generator 24
And the output signal Pb of the negative peak pulse generator 26 are shown.

Although T in FIG. 3B is equal to T in FIG. 3A, Ta in FIG.
It is longer than Ta in (a) and Tb in FIG.
Is shorter than Tb in FIG.

Further, FIG. 3C shows a case corresponding to FIG. 2C, in which the string 20 pressed by the finger at the fifth fret is shown in FIG. 3A (FIG. 2A). In the case where a string is struck at the same position as in the case of), the string waveform signal Ws immediately after the string is struck by the divided pickup 10, the output signal Pa of the positive peak pulse generator 24, and the negative peak pulse generator 26. The relationship with the output signal Pb is shown.

Although T in FIG. 3C is shorter than T in FIG. 3A, Tb in FIG.
It is equal to Tb in (a).

Therefore, in consideration of such a property of the string waveform signal Ws, by controlling the predetermined control parameter of the musical sound generating device 14 in accordance with Tb, the musical tone can be controlled by the string position.

Further, a predetermined operation may be performed on the value obtained by measuring the length of Tb to control a predetermined control parameter of the musical sound generating device 14 to control the musical sound by the string position. .

For example, in an acoustic guitar, it is known that when the strings are struck on the bridge 18 side, the sound quality is harder than that on the neck side (nut 16 side). By changing the filter characteristic of the musical sound generator 14 with the obtained value, it is possible to faithfully simulate the sound quality change that occurs in the acoustic guitar.

FIG. 4 is a flow chart showing the processing of the CPU 12 for changing the musical sound to be generated according to the change of Tb. In the present embodiment, the peak interval of the string waveform signal is measured by the peak interval measuring device 30 and the envelope is detected by the envelope detecting device 28.
It is supplied to the PU 12, and the CPU 12 generates the sounding instruction information and the cutoff frequency control information based on the supplied data.

First, processing not shown in the flowchart will be described. When the power is turned on, the initialization process is performed thereafter. In this initialization process,
Initialization processing is performed on the registers incorporated in the CPU 12, the RAM 38, and various peripheral devices.

When the initialization process is completed, a process of monitoring whether or not the string 20 has been struck is performed based on the output of the envelope detection device 28. If the series of changes in the output of the envelope detector 28 does not meet the predetermined condition, it is determined that the string is not strung, and the process for monitoring the change in the output of the envelope detector 28 is continued.

On the other hand, when a series of changes in the output of the envelope detector 28 meet a predetermined condition, it is determined that the string has been struck and the processing shown in the flow chart of FIG. Will be controlled.

Specifically, in step S402,
The measured value T of the interval (positive peak-positive peak interval) between the positive peaks of the string waveform signal Ws measured by the peak interval measuring device 30 is acquired, and in the subsequent step S404, the string measured by the peak interval measuring device 30. Measured value T1 of the interval (negative peak-negative peak interval) between the negative peaks of the waveform signal Ws
To get.

Then, based on the positive peak-positive peak interval T and the negative peak-negative peak interval T1 thus obtained, the tone pitch of the tone to be pronounced is calculated and the tone pitch of the tone to be pronounced is determined. (Step S4
06). In calculating the tone pitch of a musical tone to be sounded, for example, tone pitch = 2 / (T + T1) (reciprocal of the average value of T and T1) is calculated to obtain the tone pitch.

In the following step S408, the maximum amplitude value of the string waveform signal Ws measured by the envelope detector 28 is acquired.

Then, based on the tone pitch determined in the process of step S406 and the maximum amplitude value obtained in step S408, a tone consisting of the tone pitch information and tone intensity information based on the maximum amplitude value. Instruction information is generated (step S410).

On the other hand, in step S412, the interval from the negative peak to the positive peak of the string waveform signal Ws measured by the peak interval measuring device 30 (negative peak-positive peak interval).
Tb is acquired and the value corresponding to the string position is calculated.

Then, a predetermined offset value is added to the value calculated in step S412, and the tone generating device 14
Cutoff frequency control information for controlling the cutoff frequency of the low-pass filter is generated (step S41).
4).

In step S416, step S4
Pronunciation instruction information generated in step 10 and step S41
The cut-off frequency control information generated in 4 is supplied to the musical sound generator 14, and the musical sound generator 14 is controlled to control the digital musical tone signal of the sounding pitch and the amplitude corresponding to the sounding instruction information. Output through the low-pass filter of the cutoff frequency corresponding to the information,
A series of processing ends. The CPU 12 executes the above-described steps S402 to S41 every time there is a string.
The musical sound generator 14 is controlled by performing a series of processes up to 6.

The digital tone signal output from the tone generator 14 is converted into an analog tone signal by the D / A converter 32, and is further emitted by the acoustic device 34 as a tone that can be heard in space.

Therefore, in this electronic stringed instrument, the string 2
The negative peak-positive peak interval Tb changes according to the string position of 0, and the cut-off frequency of the low-pass filter of the musical sound generator 14 is controlled according to the change of the negative peak-positive peak interval Tb. . For this reason, when the string position is on the neck side (nut 16 side), the cutoff frequency is set low, and the cutoff frequency is set to increase as the string position moves to the bridge 18 side. When the string 20 is struck by the neck side (nut 16 side), the cutoff frequency of the low-pass filter of the tone generator 14 becomes low, and a soft tone is emitted. When the string is struck on the bridge 18 side, the cutoff frequency of the low-pass filter of the musical sound generator 14 is increased, and a musical sound having a harder sound quality is emitted.

In the above embodiment, the musical tone generating apparatus 1 is based on the negative peak-positive peak interval Tb.
The case of controlling the cutoff frequency of the low pass filter of No. 4 has been described. However, instead of controlling the cutoff frequency, any control information that the musical sound generating device 14 can recognize may be generated based on the negative peak-positive peak interval Tb.

For example, timbre balance control information for controlling the mixing balance of two kinds of timbres may be generated. When such timbre balance control information is generated, the string position is changed from the neck side (nut 16 side) to the bridge 18 side. The tone color of the generated musical tone can be gradually changed from one tone color to another tone by moving to.

Further, tone color switching information may be generated. When such tone color switching information is generated, the tone color of the musical tone to be generated is changed as the plucked string position is moved from the neck side (nut 16 side) to the bridge 18 side. You can switch one after another.

Further, pan control information for controlling the localization of the generated musical sound may be generated, and when such pan control information is generated, the string position is moved from the neck side (nut 16 side) to the bridge 18 side. According to the above, the localization of the tones generated can be gradually changed from right to left or vice versa.

Furthermore, attack level control information for controlling the attack level may be generated in the envelope of the musical tone to be sounded. When such attack level control information is generated, the plucked string position is changed to the neck side (nut 16).
It is possible to emphasize the attack of the generated musical sound as the sound moves from the side) to the bridge 18 side.

Further, pitch bend control information for controlling the time variation of the pitch bend information with respect to the generated musical sound may be generated. When such pitch bend control information is generated, the string position is bridged from the neck side (nut 16 side). It is possible to increase or decrease the time-varying pitch deviation of the generated musical sound as it moves to the 18th side. For example, as the string position is moved from the neck side (nut 16 side) to the bridge 18 side, the pitch deviation of the generated musical tone, for example, from the pitch deviated to the high tone side of the attack portion to the standard pitch Can be larger.

Further, volume control information may be generated,
When such volume control information is generated, the volume of the generated musical sound can be increased or decreased as the plucked string position is moved from the neck side (nut 16 side) to the bridge 18 side.

In the above embodiment,
The “negative peak” corresponds to the “peak of the first type” in the claims, and the “positive peak” corresponds to the “peak of the second type” in the claims. However, the tone control is performed on the basis of the waveform obtained by inverting the string waveform signal Ws shown in the above-described embodiment by adopting a circuit configuration including the output characteristics of the divided pickup or an inverting amplifier. By doing so, in that case the relationship between the positive and negative of the waveform is reversed, so
The “positive peak” corresponds to the “peak of the first type” in the claims, and the negative peak corresponds to the “peak of the second type” in the claims. It goes without saying that this also includes cases where

[0066]

Since the present invention is constructed as described above, by using only the ordinary stringed musical instrument playing method without using a special operation element such as a pedal, the generated musical tone can be struck. An effect that a change according to the position can be given is exerted.

Moreover, there is also an excellent effect that this can be realized without significantly changing the structure for measuring the peak interval, which is indispensable for pitch detection of an ordinary electronic stringed instrument.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an overall configuration of an example of an embodiment of an electronic stringed instrument provided with a musical tone control device for an electronic stringed instrument according to the present invention.

FIG. 2 is an explanatory diagram showing what kind of waveform the waveform waveform Ws of the divided pickup outputs when a string is struck, (a) shows an open string on the neck side (nut side). ) Shows the case where the string is played, (b) shows the case where the open string is played on the bridge side, and (c) shows the case where the fifth fret is pressed and the string is played at the same position as (a). .

FIG. 3 is a waveform diagram for explaining measurement of a time interval from the negative peak to the positive peak of the waveform of the string waveform signal Ws,
(A) shows the case where the open string is played on the neck side (nut side), (b) shows the case where the open string is played on the bridge side, and (c) shows that the fifth fret is pressed ( The case where a string is struck at the same position as a) is shown.

FIG. 4 is a flowchart for performing a process of changing a musical sound to be generated according to a change in the negative peak-positive peak interval Tb.

[Explanation of symbols]

10 Divided Pickup 12 CPU 14 Musical tone generator 16 nuts 18 bridge 20 strings 22 Low-pass filter 24 Positive peak pulse generator 26 Negative peak pulse generator 28 Envelope detector 30 Peak interval measuring device 32 D / A converter 34 audio equipment 36 ROM 38 RAM

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Claims (3)

(57) [Claims] 1. A waveform signal obtained by detecting string vibration
Peak time measuring means for measuring a time interval from one kind of peak to the second peak next to the first kind peak, a sound generating means for generating a musical sound corresponding to the waveform signal, and the peak interval measurement A musical tone control device for an electronic stringed instrument, comprising: a control means for controlling a mixing balance of tone colors of predetermined two types of musical tones generated by the musical tone generating means based on the time interval measured by the means. 2. A waveform signal obtained by detection of string vibration
Peak time measuring means for measuring a time interval from one kind of peak to the second peak next to the first kind peak, a sound generating means for generating a musical sound corresponding to the waveform signal, and the peak interval measurement And a control means for controlling the localization of the tone color of the musical tone generated by the musical tone generating means based on the time interval measured by the musical tone generating means. 3. A waveform signal obtained by detecting string vibration
Peak time measuring means for measuring a time interval from one kind of peak to the second peak next to the first kind peak, a sound generating means for generating a musical sound corresponding to the waveform signal, and the peak interval measurement A control means for controlling the attack level of the musical sound generated by the musical sound generating means based on the time interval measured by the means.