JP3538908B2 - Electronic musical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument in which the overtone structure of a generated musical tone is controlled in accordance with a pitch change to obtain a natural timbre change in audibility.

[0002]

2. Description of the Related Art In recent years, FFT (Fast Fourier Transform) is performed on PCM waveform data obtained by sampling instrument sounds such as natural musical instruments for each spectrum channel, and the resulting harmonic frequency value for each spectrum channel is obtained. F and an amplitude value M are stored as frame data, and a sine wave defined by an overtone frequency value F and an amplitude value M for each spectrum read from the frame data is synthesized at the time of musical tone reproduction to generate a desired tone signal. An overtone synthesis type electronic musical instrument to be formed is known. Note that such an overtone synthesis method is described in, for example,
The details are disclosed in, for example, Japanese Patent No. 4676.

[0003]

In the above-described electronic musical instrument of the overtone synthesis type, the FF for each spectrum channel is used.
The result of T analysis is stored in a frame as a discrete harmonic coefficient sequence, and the harmonic coefficient sequence is stored in a predetermined reference pitch (hereinafter referred to as a reproduction pitch).
It is generated corresponding to the CM waveform data. Therefore, when reproducing a musical tone based on such a harmonic coefficient sequence, for example, in order to provide a continuous pitch change such as pitch bend, the entire harmonic is frequency-shifted to a harmonic structure corresponding to a desired tone pitch. The harmonic frequency value F for each spectrum is controlled so as to be as follows.

In a natural musical instrument, when the pitch of a musical tone to be produced is changed, for example, as the pitch is increased, the attenuation of a higher harmonic frequency is increased, and the overtone structure changes to change the timbre. It is known that these factors are one factor in forming a tone unique to musical instruments. On the other hand, in an overtone-synthesizing electronic musical instrument, as described above, the entire harmonic is simply frequency-shifted into a harmonic structure corresponding to a desired sounding pitch. Does not change, and the tone change becomes monotonous and unnatural. The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic musical instrument that provides a natural timbre change according to a pitch change.

[0005]

[0006]

[0007]

Means for Solving the Problems To achieve the above object,
Because, in the invention described in claim 1, stores the harmonic coefficient sequence and the amplitude value coefficient sequence of the original waveform obtained by Fourier transform in the storage unit, read from the storage means when the musical sound generating harmonic An electronic musical instrument for generating a musical tone waveform formed by generating and adding a sine wave group corresponding to each of a coefficient sequence and an amplitude value coefficient sequence has a performance operator and a pitch operator. Performance information generating means for continuously varying the sounding pitch of the musical tone waveform in response to the operation of the pitch operator while generating corresponding performance information, and according to a ratio between the sounding pitch and the reproduction pitch of the original waveform. Pitch control means for shifting each harmonic frequency forming the harmonic coefficient sequence, and a plurality of coefficient tables associated with the performance information. A multiplication coefficient generation means for reading and outputting a multiplication coefficient sequence corresponding to the pitch; and a multiplication coefficient sequence output from the multiplication coefficient generation unit multiplying the amplitude value coefficient sequence, respectively, to control a harmonic structure of the tone waveform. Amplitude control means.

[0008]

According to the present invention, when the pitch operator instructs the tone pitch of the musical tone waveform in accordance with the performance operation, the pitch control means sets the harmonic coefficient sequence in accordance with the ratio between the tone pitch and the reproduction pitch of the original waveform. The amplitude value control means variably controls the amplitude value coefficient sequence corresponding to each harmonic frequency in proportion to the cent difference between the sounding pitch and the reproduction pitch. Thereby, since the harmonic structure changes with the pitch change, a natural tone change can be realized according to the pitch change.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. A. FIG. 1 is a block diagram showing a configuration of an electronic musical instrument according to an embodiment of the present invention. In this figure, reference numeral 1 denotes a performance operator provided with a keyboard or a key press / release key detection circuit, etc., which generates a key press / release key signal and a key press speed signal according to the performance operation. Reference numeral 2 denotes a performance assisting operator that is operated as a well-known pitch bender, and generates a bender operation signal corresponding to a wheel operation.
Reference numeral 3 denotes a tone designation operator provided on the instrument panel.
A tone designation signal is generated according to the setting operation.

Reference numeral 4 denotes a control unit which comprises a CPU, a ROM, a RAM, and the like, and controls each section of the musical instrument. Control unit 4
Is a key press / release signal generated by each of the operators 1 to 3,
A key pressing speed signal, a vendor operation signal, and a tone designation signal are sequentially acquired, and a key-on signal KON, a key code KC, a key pressing touch TO corresponding to a setting state of each of these operators 1 to 3 are taken.
UCH, tone color TC, frame sequence FRM
Generates SEQ and pitch bend PBEND.

Here, the key-on signal KON and the key code KC are signals representing a pressed key, and the key-touch TOUCH is a signal representing the key-depressing speed (strength) of the key. The tone color TC is data indicating a tone specified by the tone specifying signal. The frame sequence FRMSEQ is information for specifying frame data to be read from a frame data memory 5a (described later), and includes the above-described key code KC and key press touch TOUC.
H and the frame number associated with the tone color TC are designated. The pitch bend PBEND is data for variably controlling and instructing the tone pitch specified by the key code KC in response to the vendor operation signal.

Reference numeral 5 denotes a frame data generator, which includes a frame data memory 5a and a frame read control circuit 5b (not shown). Data areas corresponding to various timbres are assigned to the frame data memory 5a, and each data area stores a plurality of frame data subjected to waveform analysis prior to performance. In the waveform analysis, PCM waveform data through a plurality of band-pass filters (spectral channels) having different band center frequencies is subjected to FFT processing using, for example, continuous 2048 samples as one frame, and harmonic frequency values F and A frame time is added to the amplitude value M and stored in the frame data memory 5a. Frame data, as shown in FIG. 2, harmonic frequency value F and the amplitude value M, harmonic associated with the order n of the frame time sequence k and the harmonic coefficients sequence F ^k _n and the amplitude value coefficient sequence M ^k _n Are paired into a table.

On the other hand, a frame read control circuit 5b (not shown) selects a data area of the frame data memory 5a according to the tone color TC supplied from the control section 4, and corresponds to a frame time from the selected data area. period, reads depending on the harmonic coefficient sequence F ^k _n and the amplitude value coefficient sequence M ^k _n and the frame sequence FRMSEQ, generates a reference pitch spitch. Reference pitch SPITC
H is the pitch of the original waveform at the time of waveform analysis, that is,
It refers to the playback pitch of the sampled PCM waveform data.

Reference numeral 6 denotes a pitch information generation unit which generates pitch information PITCH (sound generation pitch) obtained by frequency-shifting a pitch frequency corresponding to the key code KC supplied from the control unit 4 in accordance with a pitch bend PBEND.
The pitch information PITCH is frequency information in units of Hz, but may be expressed in units of "cents" instead. 7 harmonic coefficient sequence in accordance with the pitch information PITCH is F ^k _n
Is a pitch control unit for controlling each overtone frequency. The pitch control unit 7 calculates a pitch ratio p (≡PITCH / SPITCH) between the pitch information PITCH (sound pitch) and the reference pitch SPITCH (reproduction pitch) by using a harmonic coefficient sequence F
^k _n is multiplied and output.

[0015] 8 equalizing coefficient eq ₁ for modifying the amplitude value coefficient sequence M ^k _n, ..., an equalizing coefficient generator for generating a eq _n. The equalizing coefficient generator 8 includes an equalizing coefficient memory 8a and an equalizing coefficient designator 8b, as shown in FIG. The equalizing coefficient memory 8a includes a plurality of coefficient tables in a three-dimensional table format. Among them, a predetermined coefficient table corresponding to the above-described frame sequence FRMSEQ, tone color TC, and key press touch TOUCH is selected and selected. Equalizing coefficient eq according to coefficient designation address AD (described later) from coefficient table
_1, ..., eq _n is read. The equalizing coefficient designating unit 8b calculates a logarithmic ratio log of the pitch information PITCH (sound pitch) and the reference pitch SPITCH (reproduction pitch).
(PITCH / SPITCH), that is, a coefficient designation address AD proportional to the cent difference between the tone pitch and the reproduction pitch is generated.

[0016] 9 is an equalizing processing unit, equalizing coefficient eq ₁ supplied from the equalizing coefficient generating unit 8, ..., the eq _n, in the multiplication to harmonic frequencies of each order in the amplitude coefficient sequence M ^k _n Control the amplitude level.
10 frame data designated by the frame sequence FRMSEQ, a frame interpolation unit for linear interpolation in accordance with the harmonic coefficient sequence F ^k _n and the amplitude value coefficient sequence M ^k _n in the front and rear frames. 11 is a sine wave synthesizing unit, based on the key-on signal KON, the harmonic coefficients are pitch control column p · F ^k _n, equalizing coefficients eq _1, ..., eq _n is multiplied amplitude coefficient sequence eq _n · M while generating a plurality of sine wave signals corresponding to the ^k _n, by adding these sinusoidal signals to output a tone waveform W. The sine wave synthesizing unit 11
In, harmonic coefficient sequence p · F ^k _n and the amplitude value coefficient sequence eq _n · M ^k _n
Based on the above, it is also possible to generate a musical tone waveform W by performing an inverse fast Fourier transform.

B. Operation of Embodiment In the above configuration, when various musical tone parameters corresponding to the performance operation are output from the control unit 4, the frame data generation unit 5 selects the data area of the frame data memory 5a according to the tone color TC, and selects the data area. frame data FRM ^k designated by the data area by the frame sequence FRMSEQ (see FIG. 4), i.e., a harmonic coefficient sequence F ^k _n and the amplitude value coefficient sequence M ^k _n is read. Next, the frame data FRM ^k thus read out is:
Is input to the pitch control unit 7, the pitch ratio p between the sound pitch and playback pitch (≡PITCH / SPITCH) is multiplied to harmonic coefficient sequence F ^k _n, thereby frame data FRM of each harmonic frequency is frequency shifted ' ^k (see Fig. 4)
It becomes.

On the other hand, the equalizing coefficient generator 8 generates equalizing coefficients eq ₁ ,..., Eq _n from a coefficient table selected corresponding to the frame sequence FRMSEQ, the tone color TC and the key press touch TOUCH, Is read out based on the coefficient designation address AD proportional to the cent difference between Then, the equalizing processing unit 9, the equalizing coefficient eq ₁ is read in accordance with the coefficient specified address AD, ..., the eq _n, frame data FRM by multiplying the amplitude value coefficient sequence M ^k _n ^"k (Fig. 4
See). As a result, a kind of filtering for changing the overtone structure of the musical tone to be generated according to the pitch bend operation amount is performed.

Here, one embodiment of the equalizing process will be described with reference to FIGS. First, when the pitch bend operation is not performed and the sounding pitch and the reproduction pitch are the same, the cent difference becomes “0”. In this case, as shown in FIG. 5A, the equalizing coefficients eq ₁ ,. , Eq _n are all “1 (0 dB)”. Accordingly, equalizing processing unit 9 outputs the amplitude coefficient sequence M ^k _n of original waveform directly to the next stage. As a result, the tone signal W output from the sine wave synthesizer 11 has the same overtone structure of the original waveform at the time of waveform analysis.

When a pitch bend operation is performed to gradually lower the sounding pitch from this state, the pitch bend operation is performed in proportion to the cent difference between the sounding pitch and the reproduction pitch, as shown in FIGS.
As shown in (2), an equalizing process is performed to increase the low-order and high-order harmonic amplitude values while reducing the middle-order harmonic amplitude values. As a result, the tone structure of the musical tone signal W output from the sine wave synthesizing unit 11 changes as the tone pitch decreases, and a natural tone change like a natural musical instrument can be obtained. On the other hand, if the pitch bend operation that gradually raises the sounding pitch is performed in reverse, the pitch bend operation corresponding to the operation is proportional to the cent difference between the sounding pitch and the reproduction pitch.
As shown in FIGS. 6A and 6B, an equalizing process for attenuating higher-order harmonic amplitude values is performed, whereby a natural tone color change at the time of pitch-up is realized.

Thus, in the embodiment described above,
Pitch information PITCH (sound pitch) and reference pitch SP
Pitch ratio to ITCH (reproduction pitch) p (≡PITCH
/ Spitch) together with shifting the multiplication to each harmonic frequency harmonic coefficient sequence F ^k _n, variably controls the amplitude coefficient sequence M ^k _n of each harmonic frequency in proportion to the St. difference between the sound pitch and playback pitch Therefore, it is possible to realize a natural tone color change according to the pitch change.

[0022] Incidentally, in this embodiment, the amplitude value coefficient sequence M ^k _n pronunciation pitch between each harmonic frequency in proportion to the St. difference between the playback pitch is variably controlled, instead of this,
Pitch information PITCH (sound pitch) and reference pitch SP
The equalizing coefficients eq ₁ ,..., Eq _n may be generated according to the pitch ratio p with respect to the ITCH (reproduction pitch).

Further, the equalizing coefficients eq ₁ ,..., E
When generating q _n , the frame sequence FRMSE
Although the coefficient table corresponding to Q, tone color TC, and key press touch TOUCH is selected, the present invention is not limited to this. For example, the parameter FRMSEQ, TC
And TOUCH, the coefficient table may be selected, or the coefficient table may be selected according to the correlation between the parameters. When reading the equalizing coefficients eq ₁ ,..., Eq _n from the coefficient table, the value of the pitch bend PBEND can be used as it is as the read address. A musical tone change like a musical instrument can be achieved.

The equalizing coefficient may be supplied in the form of an amplitude change coefficient corresponding to the order as in the above-described embodiment, or may be in the form of an amplitude change coefficient corresponding to a frequency, for example. In this case, the corresponding to each harmonic coefficient sequence p · F ^k _n output from the pitch control unit 7 determines the amplitude change coefficient variably controls the amplitude coefficient sequence M ^k _n of each harmonic accordingly . In the above embodiment, the frame interpolation is performed after performing the equalizing process. Alternatively, the equalizing process may be performed after the frame interpolation. When a coefficient table is selected according to the frame sequence FRMSEQ, it is possible to generate an equalizing coefficient by changing the coefficient table to be selected between the attack part frame and the sustain part frame. Each component configuration is composed of hardware, CPU, DSP
It can be realized by using such as appropriate.

[0025]

According to the present invention, when the pitch operator instructs the tone pitch of the musical tone waveform in accordance with the performance operation, the pitch control means causes the overtone in accordance with the ratio between the tone pitch and the reproduction pitch of the original waveform. Shift each harmonic frequency forming the coefficient sequence,
Since the amplitude value control means variably controls the amplitude value coefficient sequence corresponding to each harmonic frequency in proportion to the cent difference between the sounding pitch and the reproduction pitch, the harmonic structure changes with the pitch change, and A great tone change.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an electronic musical instrument according to one embodiment of the present invention.

FIG. 2 is a diagram for explaining a form of frame data in the embodiment.

FIG. 3 is a block diagram showing a configuration of an equalizing coefficient generator 8 in the embodiment.

FIG. 4 is a diagram for explaining an equalizing process in the embodiment.

FIG. 5 is a diagram for explaining the operation of the embodiment.

FIG. 6 is a diagram for explaining the operation of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... performance operator (pitch operator), 2 ... performance assist operator (pitch operator), 4 ... control part, 5 ... frame data generation part (overtone coefficient sequence and amplitude coefficient sequence), 6 ... pitch Information generation unit, 7: pitch control unit (pitch control unit), 8: equalizing coefficient generation unit (amplitude value control unit), 9: equalizing processing unit (amplitude value control unit), 10: frame interpolation unit, 11: sine wave Synthesis unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G10H 1/00-7/12

Claims (1)

(57) [Claims] 1. An overtone coefficient sequence and an amplitude value coefficient sequence obtained by performing a Fourier transform on an original waveform are stored in a storage means, and the overtone coefficient sequence and the amplitude value coefficient sequence read from the storage means when a musical tone is generated are respectively stored. An electronic musical instrument for generating a musical tone waveform formed by generating and adding a corresponding sine wave group includes a performance operator and a pitch operator, and generates performance information corresponding to the operation of the performance operator. Performance information generating means for continuously varying the sounding pitch of the musical tone waveform in accordance with the operation of the pitch manipulator; and each of forming the harmonic coefficient sequence according to a ratio between the sounding pitch and the reproduction pitch of the original waveform. Pitch control means for shifting a harmonic frequency, and a plurality of coefficient tables associated with the performance information, wherein a multiplication corresponding to the tone pitch is performed from a predetermined coefficient table selected according to the performance information. Multiplication coefficient generation means for reading and outputting a coefficient sequence; and amplitude value control means for multiplying the amplitude value coefficient sequence by the multiplication coefficient sequence output from the multiplication coefficient generation means, respectively, and controlling a harmonic structure of the musical tone waveform. An electronic musical instrument comprising: