JPS5820039B2 - electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the voice (timbre) of an electronic musical instrument, and particularly to modulating the harmonics contained in the generated sound as a function of the attack and decay opening times.

Generally, in many natural musical instruments, each harmonic varies as a different function of time.

At the attack or beginning of the sound, higher frequency harmonics are predominant.

Thereafter, lower harmonics gradually begin to contribute to the overall volume, eventually achieving a unique timbre.

Similarly, in decay, higher frequency harmonics disappear faster than lower order components.

The object of the present invention is to realize the above-mentioned time-dependent harmonic modulation during the attack and decay of the sound generated by an electronic musical instrument.

The above purpose is as follows.
This is accomplished in an electronic musical instrument of the type described in the specification of No. 90217).

In this type of electronic musical instrument, the musical tone is the amplitude value X of sequential sample points qR of the musical sound waveform.

(qR) in real time and converting the amplitude value into sound while performing this calculation.

The valley sample point amplitude values are calculated at regular time intervals tX according to the following equation.

Here, q is a variable that increases with each time interval tx,
The value n=1.2.3...W represents the order of the Fourier component to be calculated, and R is the frequency number establishing the fundamental frequency of the generated musical tone.

Attack and Decay are time-dependent scale factors that describe the amplitude envelope of the generated sound.
S(t).

Harmonic modulation according to the present invention is accomplished by using separate attack and decay scale factors for each harmonic component.

In other words, the waveform amplitude value is calculated according to the following equation.

Here, a separate scale factor 5(t)n is provided for each Fourier component, respectively.

The invention will now be described in detail with reference to embodiments of the accompanying drawings.

The timbre improvements disclosed herein are performed in conjunction with the basic electronic musical instrument 10 shown in the figures.

With this device, each time one of the keyboard switches 11 is pressed, a corresponding sound is emitted from the sound system 12.
The timbre of the voiced sound generated through the harmonic coefficient memory 13 is set by a set of harmonic coefficients Cn stored in the harmonic coefficient memory 13.

This basic electronic musical instrument 10 performs C operation according to the first equation and generates sound.

First, the operation of the electronic musical instrument 10 as described above will be explained.

Sequential waveform sample point amplitude value X.

(qR) is calculated at regular time intervals tx according to the first equation above.

In this example, up to W=16 individual Fourier components are calculated separately in corresponding calculation times tcp1 to tCp16.

This calculation time is established by a pulse generator 16 supplying pulses via line 17, modulo W-16 counter 18 (every time interval tcp).

The contents of counter 18 represent the order n of the Fourier component currently being calculated.

A signal representing the order n is provided on line 19.

The timing pulse of the calculation time tx is supplied to the line 20 by delaying the reset pulse of the counter 18 (occurring at time t c p +6) slightly by a delay circuit 21 .

The fundamental frequency of the generated sound is established by the frequency number R read out from the frequency number memory 23 in response to the selection of the keyboard switch 11.

At the beginning of each calculation time tx line 24, gate 2
The number R supplied via 5 is added to the previous contents of the phonetic calculator 26.

The contents of adder 26 provided via line 27 represent a value (qR) representing the waveform sample point currently being calculated.

Preferably, the tone calculator 26 is modulo 2W, where W is the highest harmonic component calculated by the device 10.

In this example, 16 Fourier components are sufficient to synthesize most pipe organ sounds, so W
-16.

Each calculation timing pulse tcp is supplied to gate 28 via line 17.

This gate 28 supplies a value qR to a harmonic adder 29 which is cleared at the end of each amplitude calculation time tx.

In this way, the contents of the harmonic adder 29 are calculated at each calculation time t c
p1~tCp1 is increased by the value qR, and the content of adder 29 represents the quantity (nqR).

This value is obtained on line 30.

Address decoder 31 receives variable t from line 30.
A value s ln w n q R corresponding to t q R is read from the sine function storage device 32 .

The sine function storage device 32 can be configured as a read-on memory that stores the value of Singφ in the range of 0≦φ≦W and at intervals of π.

Here, D is a memory division constant. According to this configuration, at the first calculation time tcp1, the value s ln w q
R is supplied to line 33.

At the next calculation time tcp2, the value S 1 n w 2 q
R is supplied to line 33.

Thus, in general, the value of the individual nth order component, π s 1n w n qR, specified by the contents of the counter 18, is provided from the sine function storage 32.

As mentioned above, the set of harmonic coefficients Cn is stored in the harmonic coefficient memory 13.

When the value of each sine function is supplied to the line 33, the harmonic coefficient Cn of the corresponding nth component is read out from the memory 13 by the memory address control circuit 36 which receives the value from the line 19. Ru.

The read value Cn is supplied to a harmonic coefficient scaler 38r via an input 37, where it is multiplied by the amplitude scale factor S(t) of the attack/decay occurring at an input 39. .

The multiplication result 5(t)nCn fed via line 40 is the value s from line 33 in harmonic amplitude multiplier 41G.
It is multiplied by 1n w n q R.

The output of multiplier 41, which corresponds to the value of the Fourier component currently being calculated, is applied via line 42 to accumulator 43.

The separately calculated Fourier components are summed in an accumulator 43.

At the end of each calculation time interval tx, the content of accumulator 43 is the waveform amplitude value X of the current sample point qR.

(qR) is expressed. On line 20 (this time tx
When a pulse occurs, the contents of accumulator 43 are transferred to digital-to-analog converter 47 via gate 44.

The accumulator 43 is then cleared in preparation for the summation of the Fourier components for the next sample point, ie, the calculation begins immediately.

Digital-to-analog converter 47 provides a voltage corresponding to the now calculated waveform amplitude to sound system 12.

Since these calculations are performed in real time, the analog voltage from the converter 47 constitutes a musical sound waveform with a fundamental frequency established by the frequency number H then supplied from the memory 23.

A scale factor 5(t)n is added from a set of memories 160 as an element for each Fourier component.

For example, during the calculation of the fundamental (low 1) Fourier components,
The harmonic coefficient C0 of line 37 is obtained from counter 18 by signal n
It is scaled (weighted) by the scale factor 5(t)1c added from note 1J 160-1 via gate 161-1 enabled by 21.

Similarly, the remaining Fourier components of orders n-2 to n-16 are added by separate scale factors 5(t)2 to 160-16 and their associated gates 161-2 to 161-16. 5(t)161, respectively.

Each of the memories 160 is read out from the corresponding seven memory read control circuits 162-1 to 162-16+.

These control circuits 162 all correspond to the contents of the attack/decay period counter 163, and this counter 1
63 counts quarter, half and full period pulses applied via line 53 from tone counter 26.

Thus, the scale factor 5(t)n is selectively updated as the attack and decay opening times progress.

This update is not bound by the frequency of the sound being generated.

Alternatively, counter 163 may count pulses from any rank pulse generator 164 shown in phantom in the figure.

The counter 163 is set at the beginning of attack and decay.

This is executed by applying the key press signal kP and the decay start signal DS to the reset terminal of the counter 163 via the OR gate 165.

Flip-flop circuit 166 indicates to control circuit 162 whether attack A or decay D is in progress.

The 79717171 circuit 166 is set by the Decay Start signal DS on line 124.

And when the preset count is reached, the counter 16
It is reset by the decay end signal DF obtained from 3.

This decay end signal DF is also applied to attack/decay control logic 49 (via line 131) to reset flip-flop circuit 118.

Flip-flop 166 is set to a ``1'' state only during decay and remains at a ``0'' state during attack and sustain.

Reading of the attack scale factor from memory 160 begins when keyboard switch 11 is closed.

Opening of this switch causes a key press signal KP to be generated on line 50 to initiate the attack.

The sequential scale factor 5(t)n is the switch 51
Depending on the settings, the entire (1) or half (, -) i of the sound being generated is read out from the memory 160 every cycle.

Since the tone calculator 26 is modulo 2W, the count reaches 3 at the end of each period of the selected tone.

At this time, an output is produced on line 52. Now, with switch 51 in the position shown in FIG. 2, signal line 53i is generated at the end of a complete period of sound production.

In each half cycle, the tone calculator 26 reaches a count of 16 or 32.

The corresponding output is supplied to the terminal 55 of the switch 51 via the OR gate 54.

Similarly, for one period pulse, the tone calculation unit 26 has a count value of 8, 16.
, 24 or 32, 55g of OR gate is supplied.

At each of these arrival times, one periodization signal is applied to terminal 57 of switch 51.

The setting of switch 51 thus determines whether full, half or one period pulses are provided on line 53 and at what intervals the scale factor 5(t)n is sequentially read from memory 60. Determine.

The above-described reading operation of the active sustain scale factor memory 60 is started each time the keyboard switch 11 is closed.

For example, if the C7 tone is selected by closing the corresponding switch 110, one-shot multi-by-break 113 is transmitted via line 111, or gate 112.
A signal is added to

As a result, a key press signal KP is generated on line 50 to start reading out the memo January 60.

Reading of the decay scale factor from memory 60 begins when the selected keyboard switch 11 is released.

In order to continue sounding throughout the decay period (the frequency number memory 23 is read out in response to the flip-flop groups 118 respectively associated with the corresponding keyboard switches 11).

Therefore, the switches 110, . . . 119 and 120 for the C7 sound, .
1 Connected to set human power S of Br.

For example, when switch 110 is closed, flip-flop 118-1 is set and a signal is provided on line 121 to read the frequency number R associated with C7 note G from memory 23.

Even if the key switch 110 is released, the flip-flop 1
18-1 is not reset immediately.

Therefore, the signal on the input 121 remains at a high level,
The selected frequency number R is stored in memory 2 during the decay period.
It continues to be read from 3.

However, opening switch 110 causes the output of ORG-N12 to go low.

Therefore, the inverter 122 sends out a high level output that triggers the one-shot multi-byte break 123.

This trigger generates a decay start signal DS on line 124.

Decay end signal DF, which also occurs on line 131, resets all flip-flops 118 and memory 23
The reading of the selected frequency number is finished, and the sound generation is stopped.

As explained above, this invention (according to this invention) allows the amplitude of each high frequency that constitutes a musical tone to be controlled by using a plurality of amplitude scale factors that change over time, so that natural musical instruments can It is possible to generate musical tones that are full of naturalness, with the open tone color of attack and decay changing in the same way as the sound itself.

[Brief explanation of drawings]

The figure is a block diagram showing one embodiment of the present invention. 160...Attack/decay memory, 162
...Memory read control circuit, 163...
・Attack/decay cycle counter.

Claims (1)

[Claims] 1. In an electronic musical instrument in which the amplitude values of sequential sample points of a musical sound waveform are calculated by individually calculating each Fourier component at the sample point and summing these components, the amplitude values are A first step that generates a plurality of time-varying amplitude scale factors.
and a second device for controlling the amplitudes of corresponding Fourier components using the plurality of amplitude scale factors.