JPH0721714B2 - Music synthesizer - Google Patents

Description

The present invention relates to a musical sound synthesizing apparatus, and more particularly to a musical sound synthesizing apparatus for inputting a non-linear signal to a closed loop including a delay means to circulate and process the musical sound.

[Prior Art] Conventionally, there is known a signal processor of a so-called waveguide system, which synthesizes a musical sound by inputting waveform data into a closed loop including a delay circuit and performs arithmetic processing on the musical sound, or imparts a special effect such as reverberation to the musical sound. (For example, JP-A-63-40199).

Since this signal processor is a physical approximation of a mechanical vibration system of a natural musical instrument such as a wind instrument string or a stringed string instrument by an electric circuit, the closed loop includes a lead or an emboucher of a wind instrument or a bow of a stringed instrument. If a non-linear signal corresponding to the movement of the contact point with the string was input, the sound of the wind instrument's rubbed string instrument could be naturally and faithfully synthesized, including changes due to its strength.

However, in reality, it is difficult to express nuances that are natural to musical instruments and to control synthetic sounds by various performance parameters with conventional electronic musical instruments that use a nonlinear musical sound synthesizer that inputs a nonlinear signal to such a signal processor. Met.

This is for the following reason.

That is, in such a nonlinear tone synthesizer,
One or more fixed non-linear tables have been used as non-linear signal sources. Even when a plurality of nonlinear tables are used, one table is selected according to a certain control variable, and one nonlinear signal is generated in one table. Therefore, the number of types of non-linear signals is limited to the same number as that of the table, and the range of selection is narrow.Therefore, the electronic musical instrument using such a non-linear musical tone synthesizer has a limited expressive power, and can express nuances that are natural musical instruments. It has been difficult to control synthetic sounds with various performance parameters.

[Problems to be Solved by the Invention] The present invention has been made in view of the problems in the above-described conventional example, and can generate a wider variety of musical sounds by using a limited number of function generating means (for example, a table). It is an object of the present invention to provide a musical tone synthesizer configured as described above.

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a closed loop means including a delay means, a non-linear signal is generated by using a performance operation signal and a signal extracted from the closed loop means as variables, and the closed loop means is generated. In a musical tone synthesizing device including a non-linear function generating means for giving a means, the non-linear function generating means is provided with a hysteresis characteristic, and the hysteresis characteristic is determined according to the performance operation signal or a control signal corresponding to a predetermined musical tone parameter. It is characterized by change control.

[Operation] According to the above configuration, the nonlinear function generating means has a hysteresis characteristic, and the hysteresis characteristic is
The change control is appropriately performed according to the performance operation signal and the tone parameter.

Therefore, in the present invention, various nonlinear signals are appropriately generated according to the performance operation signal and the musical tone parameter,
It can be fed to the closed loop.

[Effect] As described above, according to the present invention, since various hysteresis characteristics can be obtained with a limited number of function generating means, various musical tones can be synthesized.

[Examples] Hereinafter, the present invention will be described in detail based on examples.

FIG. 1 shows the configuration of a musical tone synthesizing apparatus to which the nonlinear function generating apparatus of the present invention is applied.

The device shown in the figure is for synthesizing playing sounds of a stringed instrument such as a violin by digital data arithmetic processing, and includes delay circuits 1a and 1b, low-pass filters (LPF) 2a and 2b, and multipliers 3a and 3
b, adders 4a, 4b, 5, 6 and a non-linear function generator 7 are provided.

Delay circuits 1a, 1b, LPFs 2a, 2b, multipliers 3a, 3b and adder 4
The closed loop consisting of a and 4b corresponds to the string rubbed by the bow, and the delay time of the closed loop corresponds to the resonance frequency of the string.

The delay time of the delay circuits 1a and 1b and the transfer characteristics of the LPFs 2a and 2b are controlled by a control circuit (not shown) based on the calculation information.

The multipliers 3a and 3b multiply input signals by "-1" and output the same, and are used as phase inverters. Note that this multiplier can also be used as a subtractor by multiplying by a constant whose absolute value is smaller than 1.

The adders 4a and 4b correspond to the chord points, and the closed loop corresponds to both sides of the chord points of the chords and the delay circuits 1a and LPF2.
The first signal path consisting of a and the multiplier 3a and the delay circuits 1b, L
A second signal path consisting of PF2b and multiplier 3b and an adder 4a
And 4b are separated.

The non-linear function generator 7 outputs a signal obtained by adding the signal representing the bow velocity Vb to the signal obtained by adding the output of the first signal path and the output of the second signal path by the adder 5 to each other. An input / output characteristic function as shown in FIG. 2 is output for each instantaneous level of the input signal.

This function output signal is added to the outputs of the second and first signal paths in adders 4a and 4b, respectively, and then input to the first and second signal paths.

The input / output characteristic shown in FIG. 2 represents the friction characteristic between the bow and the string, and has the nonlinear characteristic and the hysteresis characteristic due to the transition from the static friction to the dynamic friction. Further, since the static friction increases as the arch pressure increases, this hysteresis characteristic changes depending on the arch pressure Fb.

As described above, the apparatus of FIG. 1 physically approximates a mechanical vibration system such as a string of a rubbed string instrument and a drive system between a bow and a string by an electric circuit (hereinafter referred to as a physical model). If the accuracy is high, the sound of the actual musical instrument can be accurately reproduced.

FIG. 3 shows the structure of a function generator according to an embodiment of the present invention. The apparatus shown in FIG. 1 is used as a function generator 7 in the apparatus shown in FIG. 1 to generate a non-linear function having a hysteresis characteristic.
2, multiplier 13-17, selector (or multiplexer) 1
8 to 20, comparators 21 and 22, an OR circuit 23, and a delay circuit 24.

The function table 11 stores the data (Vs obtained by adding the bow velocity Vb by the adder 6 to the data Vs obtained by adding the data output from the first signal path and the data output from the second signal path).
+ Vb) is input as an address, and a hyperbolic function as shown in FIG. 4 is generated. This hyperbolic function represents the dynamic friction characteristic between the bow and the chord.

The function table 12 generates a linear function as shown in FIG. 5 by using the input data (Vs + Vb) as an address. This linear function represents the static friction characteristic between the bow and the chord.

The multiplier 13 outputs the bow pressure Fb to the hyperbolic function output of the function table 11.
By multiplying by, the hyperbolic function output is biased according to the bow pressure Fb.

Multipliers 14 to 17 apply constants t0p1, t1pt, t0m to the bow pressure Fb, respectively.
Threshold data corresponding to the arch pressure Fb is generated by multiplying by 1, t1m1. Where t0p1 and t1p1 are positive values, t0m1
And t1m1 are negative values.

The comparator 21 outputs "1" as a comparison signal when the input data (Vs + Vb) is larger than the threshold value (t0p1 or t1p1) selected by the selector 18, and outputs "0" when it is smaller.

The comparator 22 determines whether the input data (Vs + Vb) is greater than the absolute value of the threshold value (t0m1 or t1m1) selected by the selector 19, or
The comparison signal “0” or “1” is output depending on whether it is smaller.

The OR circuit 23 synthesizes the comparison signals output from the comparators 21 and 22. The output of the OR circuit 23 is input to the delay circuit 24 and is also supplied to the selector 20 as a selection signal.

The delay circuit 24 slightly delays and outputs the comparator signal output from the OR circuit 23.

Next, the operation of the apparatus shown in FIG. 3 will be described with reference to FIGS.
Description will be given with reference to the drawings.

First, when the input data (Vs + Vb) is 0, the outputs of the comparators 21 and 22 are both "0", and the output of the OR circuit 23 is also "0". Further, as will be described later, the output of the delay circuit 24 is also "0". Therefore, the selector 18 sets the threshold t1
p1 is selected and supplied to the comparator 21, and the selector 19 sets the threshold value t1m1
Is supplied to the comparator 22, and the selector 20 selects the output of the function table 12 (FIG. 5). When the input data (Vs + Vb) increases from this state and exceeds the threshold value t1p1, the output of the comparator 18 becomes "1" and the output of the OR circuit 23 also becomes "1". The selector 20 selects the hyperbolic function output (FIG. 4) of the function table 11 according to this signal "1". As a result, the output Vo of the selector 20, as shown in FIG.
After the input (Vs + Vb) increases linearly from 0 in accordance with the linear function, the input (Vs + Vb) discontinuously shifts to the hyperbolic function at the point where it exceeds the threshold value t1p1 and decreases non-linearly. After that, if the input (Vs + Vb) further increases, the output Vo
Decreases linearly according to the hyperbolic function. At this point, the output of the delay circuit 24 is "1", and the selector 18 gives the threshold value t0p1 to the comparator 21.

Next, when the input (Vs + Vb) begins to fall, the output Vo rises linearly according to a hyperbolic function. And input (Vs + V
When b) becomes the threshold value t0p1, the output of the comparator 21 becomes "0" and the output of the OR circuit 23 also becomes "0". As a result, the selector 20 selects the output (FIG. 4) on the function table 11 side, and the output Vo rises discontinuously (non-linearly) as shown in FIG. After that, when the input (Vs + Vb) further decreases, the output
Vo falls linearly (linearly) according to the linear function of FIG. At this point, the output of the delay circuit 24 is "0" as described above, and the selectors 18 and 19 select the threshold values t1p1 and t1m1, respectively. Therefore,
As long as the input (Vs + Vb) changes between the threshold values t1p1 and t1m1, the output Vo becomes the linear function of FIG.

On the other hand, when the input (Vs + Vb) has a negative value, the selector 19 and the comparator 22 are connected to the selector 18 and the comparator 21.
Works the same as. That is, the input (Vs + Vb) is the threshold t1.
When it becomes lower than m1, the comparator 22 detects this and switches the output Vo from the linear function of FIG. 4 to the hyperbolic function of FIG.
Furthermore, the input (Vs + Vb) rises from this state and the threshold value t0
When m1 is reached, the output Vo is switched from the hyperbolic function of FIG. 5 to the linear function of FIG.

As described above, the device shown in FIG. 3 uses the two functions shown in FIGS. 4 and 5, and when the function shown in FIG. 4 is referred to, the input value to the device is t1m1. When the value becomes less than or exceeds t1p1, it transits to the function of FIG. 5, and when the function of FIG. 5 is referenced, the input value to the device exceeds t0m1. It is a value, but t0p1
When the value falls below the value, a non-linear function having hysteresis as shown in FIG. 2 can be generated by transitioning to the function of FIG.

FIG. 6 shows a modification of the device of FIG.

These devices are used as the non-linear function generator 7 in the device of FIG. 1, and try to control the non-linear shape and properties in order to diversify the timbre and expressiveness of the synthesized sound of the device of FIG. To do. In the apparatus shown in FIG. 3, a hysteresis is introduced non-linearly, and the width of the hysteresis and the magnitude of the non-linear function are controlled by inputting performance information. The apparatus of FIG. 6 further controls the non-linear height, inclination, size, transition level and the like according to control variables and the like input from an operator such as a keyboard.

Here, the width of hysteresis is shown in Fig. 2 (t1m1
And t0m1), (t0p1 and t1p1), which are the coefficients t1m1, t0m1, t0p1, t1p in the apparatus of FIGS. 3 and 6.
It can be realized by rewriting 1. This is effective when the shape depends on the magnitude of the bow pressure Fb and the greater the bow pressure Fb, the larger the difference.

The transition level of hysteresis is t1m1, t in Fig. 2.
It means the absolute value of 0m1, t0p1, t1p1. This control is
It can be performed by the same method as the control of the difference between these values (width of hysteresis) described above.

The apparatus shown in FIG. 6 is different from the apparatus shown in FIG. 3 in that multipliers 61 and 62 to which a multiplier corresponding to performance data is given from the control circuit 60.
Is added.

In the apparatus shown in FIGS. 3 and 6, the non-linear function having hysteresis as shown in FIG. 2 is realized by the two functions shown in FIGS. 4 and 5, and its behavior is as shown in FIG. When the input value to the device becomes less than t1m1 or more than t1p1 when the function in the figure is referred to, it transits to the function in FIG. When the function is referred to, when the input value to the device exceeds the value t0m1 or falls below the value t0p1, the function transits to the function shown in FIG. To realize the hysteresis of this non-linear function, the table of the two functions shown in FIGS. 4 and 5 is used to determine which of the function table values is to be adopted according to the result of comparison between the input and a certain threshold value. It is done by the method of making a decision. The certain threshold may be a predetermined value or may be changed by a control parameter such as bow pressure.

In the device of FIG. 3, four constant data t0p1, t1p1,
t1m1 and t0m1 are prepared, and a value obtained by multiplying them by the bow pressure Fb is used as a threshold value. The delay circuit 24 stores which of the two function tables was referred to last time. Depending on the state of this delay circuit 24, (t0p1
And t0m1) or (t1p1 and t1m1) are compared with the input value to the device to determine which of the two function tables is to be referenced. As a result, a non-linear function having hysteresis as shown in FIG. 2 can be realized.

In the function generator 7 of the apparatus shown in FIG. 1, when the height, slope, hysteresis magnitude transition level, etc. of the nonlinear function are further changed, the rising speed of the synthesized sound, the tone color, and the easiness of pronunciation Changes. Therefore, changing these parameters from the performance operator as necessary is effective in terms of timbre diversification and improvement of expressiveness.

Here, the non-linear height corresponds to an asymptotic line with respect to the horizontal axis (input axis) when the function of FIG. 5 is considered as a hyperbola, and the control thereof is performed by the multiplier 13 or 61 of FIG. It may be given as a coefficient.

The non-linear slope is the slope of the straight line in FIG. 4, and control of this can be realized by controlling the coefficient of the multiplier 62 in FIG.

[Modifications of the Embodiment] The present invention is not limited to the above-described embodiments, and can be modified and implemented as appropriate.

For example, in the above-described embodiment, the hysteresis threshold value is given as a value obtained by multiplying the bow pressure Fb by giving a predetermined coefficient (constant) to the multipliers 14 to 17, but this coefficient or the threshold value itself is shown. If is treated as a variable controlled by the information from the performance information input device, a large timbre change is possible, and a wide range of expression power can be provided. For example, the width of hysteresis, that is, the threshold (t1m1 and t0m1),
If the difference between (t0p1 and t1p1) is changed by the bow pressure Fb, the timbre can be changed by the bow pressure Fb. In this case, for example, the width of hysteresis may be increased for strong bow pressure and the width of hysteresis may be decreased for weak bow pressure.

Further, in the multiplier 13 shown in FIGS. 3 and 6, the output of the function table 11 is multiplied by the bow pressure Fb, but this multiplication causes a change in the jump width at the non-linear transition. If the multiplier 13 is not simply multiplied by Fb but is multiplied by a function of Fb, the range of expression power due to the bow pressure can be further increased. Further, other performance information parameters such as bow speed may be used instead of bow pressure.

It is also effective to change the threshold value according to the thickness of the string of the pitch. In addition, when synthesizing a sound other than the stringed instrument sound, the non-linear transition can be reversed.

Further, in the above description, an example of generating a nonlinear function having hysteresis and controlling the width and height of the hysteresis and the transition level has been described.
It is also possible to generate a non-linear function without hysteresis, and again the transition level can be controlled in the same way as described above.

Furthermore, in the above description, an example in which the present invention is applied to a stringed instrument sound synthesizer has been described, but the present invention is also effective when applied to other musical tone synthesizers such as wind instruments and artificial sounds. Even when applied to a non-linear tone synthesizer such as a wind instrument, the height, inclination, size, transition level and the like can be controlled in exactly the same manner as in the above-mentioned stringed instrument sound.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing the configuration of a musical tone synthesizer to which the nonlinear function generator according to an embodiment of the present invention is applied, and FIG. 2 is a graph showing the output function of the nonlinear function generator. FIG. 3 is a block circuit diagram showing the configuration of a non-linear function generator according to an embodiment of the present invention, and FIGS. 4 and 5 are graphs showing functions stored in the function table in FIG. 3, respectively. FIG. 6 is a block circuit diagram showing the configuration of a non-linear function generator according to another embodiment of the present invention. 11, 12: Function table 13-17: Multiplier 18-20: Selector (multiplexer) 21, 22: Comparator 24: Delay circuit

Claims (2)

[Claims] 1. A tone synthesizer comprising: a closed loop means including a delay means; and a non-linear function generating means for generating a non-linear signal by using a performance operation signal and a signal taken out from the closed loop means as variables, and giving the closed loop means to the closed loop means. A tone synthesizing apparatus characterized in that the non-linear function generating means is provided with a hysteresis characteristic, and the hysteresis characteristic is changed and controlled according to the performance operation signal. 2. A tone synthesizer comprising: a closed loop means including a delay means; and a non-linear function generation means for generating a non-linear signal by using a performance operation signal and a signal extracted from the closed loop means as variables and giving the non-linear function to the closed loop means. A musical tone synthesizing apparatus comprising: a control means for generating a control signal corresponding to a musical tone parameter, the non-linear function generating means having a hysteresis characteristic, and changing and controlling the hysteresis characteristic according to the control signal.