JPH04133099A - Musical sound synthesizer - Google Patents

Abstract

PURPOSE:To reflect delicate representation of the musical sound of a musical instrument by a player by providing an output information detecting means which detects the output information of a sound generating operation element and a control means which generates a control signal for varying characteristics of musical sound synthesis according to the output of the detecting means. CONSTITUTION:An output information detecting circuit 3 consists of a low-pass filter 4, a pitch extracting circuit 5, etc. Then a CPU 7 which outputs a necessary signal by controlling respective parts of a musical sound synthesis block for musical sound synthesis is installed. At this time, the CPU 7 constitutes a control means 10 with a band-pass filter 8 and a ROM 9. Once the output information of the sound generating operation element is detected, the control means 10 generates the control signal for varying the characteristics of musical sound synthesis according to the output information and a musical sound generation part including a closed loop circuit 13 synthesizes the musical sound of a natural musical instrument while varying the characteristics of musical sound synthesis according to the control signal. Consequently, a musical sound that the player desires can be outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a musical tone synthesis device suitable for use in musical tone synthesis for plucked string instruments, percussion instruments, and the like.

"Prior Art" Conventionally, devices have been known that synthesize tones of natural instruments by simulating the sound production mechanism of natural instruments. 2. Description of the Related Art As a musical sound synthesis device for stringed instrument sounds, one is known that has a structure in which a low-pass filter that simulates the vibration loss of strings and a delay circuit that simulates the propagation delay of vibrations in the strings are connected in a closed loop. In such a configuration, when an excitation signal such as an impulse is introduced into the closed loop circuit, this excitation signal circulates within the closed loop. In this case, the excitation signal goes around the closed loop in a time equal to the vibration period of the string, and is band-limited when passing through the low-pass filter. The signal circulating in this closed loop is then extracted as a musical tone signal of the stringed instrument.

According to such a musical tone synthesis device, by adjusting the delay time of the delay circuit and the characteristics of the low-pass filter,
It is possible to synthesize musical sounds that are close to natural string instrument sounds, such as the sounds of plucked string instruments such as guitars, and percussion instruments such as piano. Furthermore, musical tone synthesis of the sounds of a bowed string instrument such as a violin is realized by connecting an excitation circuit that calculates vibrations that excite the strings by a bow to the above-mentioned closed loop circuit. Note that this type of technology is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-40199 or Japanese Patent Publication No. 58-58679.

``Problems to be Solved by the Invention'' However, although the conventional musical tone synthesis device described above is capable of synthesizing a variety of musical tones, it is difficult to reflect the subtle expressions of musical tones of musical instruments by the performer. However, there were problems in that they were inferior in many respects compared to natural instruments.

That is, with the techniques described in the above publications, it is possible to faithfully synthesize musical tones, but on the other hand, the input of performance information is not taken into consideration much, and as a result, it is difficult to output musical tones desired by the performer.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a musical tone synthesis device that takes into account the input of performance information and can reflect subtle expressions of musical tones of musical instruments by a performer.

"Means for Solving the Problems" In order to solve the above-mentioned problems, the present invention provides a sound generation operation that simultaneously excites a sounding body and a part of the sounding body to generate vibrations that propagate back and forth through the sounding body. and a musical tone forming section including a closed loop circuit in which a low-pass filter that simulates vibration loss of the sounding body and a delay circuit that simulates propagation delay of vibration in the sounding body are connected in a closed loop. J further comprises an output information detection means for detecting output information of the sound production operator, and a control means for generating a control signal for changing characteristics of musical tone synthesis based on the output of the output information detection means, and the closed loop circuit is configured to control The present invention is characterized in that musical tones are synthesized while varying characteristics of musical tone synthesis based on a control signal from the means.

"Function" In the present invention, when the output information of the sound generation operator is detected, the control means generates a control signal that changes the characteristics of musical tone synthesis based on the output information, and the musical tone forming section including the closed loop circuit generates a control signal that changes the characteristics of musical tone synthesis. Musical sounds of natural musical instruments are synthesized while varying the characteristics of musical sound synthesis based on the signal.

Therefore, the performer's subtle expression of the musical tone of the instrument is reflected.

"Example" Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. This musical tone synthesis device synthesizes musical tones produced by conventional plucked string instruments such as electric guitars. In this figure, 1 is an electric guitar with a normal configuration as a musical tone operator, and an output information detection circuit 3 is connected to an interface 2.
is connected to. The electric guitar 1 has a plurality of strings as sounding bodies, and when a part of the strings is struck, it is excited and generates vibrations that propagate back and forth through the strings. The ink-face 2 includes, for example, a low-pass filter for preventing unnecessary noise, an A/D converter, and the like.

The output information detection circuit (corresponding to output information detection means) 3 includes a low-pass filter 4, a pitch extraction circuit 5, and a rising edge detection circuit 6. The low-pass filter 4 extracts a so-called envelope signal from the musical tone output from the electric guitar 1, and supplies the output to a multiplier 19, which will be described later. The pitch extraction circuit 5 extracts pitch information (corresponding to frequency) of the musical tone output from the electric guitar 1 and sends it to the CPU 7.
The rising edge detection circuit 6 similarly detects the rising edge of the output musical tone. The CPU 7 controls each section of the musical tone synthesis block for musical tone synthesis, and outputs necessary signals, such as a delay signal DL, address information, and a signal to the bandpass filter 8. The CPU 7 constitutes a control means 10 together with a band pass filter (BPF) 8 and a ROM 9. ROM9
stores the processing programs and data necessary for musical tone synthesis. The bandpass filter 8 filters signals in a predetermined range from the musical tones output from the electric guitar 1, and its output is supplied to the multiplier 11. As a result, while normally only musical tones can be synthesized based on waveforms stored in the drive waveform memory 17, which will be described later, detailed control by the performer can be reflected in the synthesized musical tones.

Note that the characteristics of the bandpass filter 8 are controlled by the output signal from the CPU 7, and specifically, the filter characteristics change depending on the pitch information described above.

Further, an operation panel 12 is connected to the CPU 7,
The operation panel 12 outputs to the CPU 7 operation signals necessary for musical tone synthesis operated by the performer.

13 is a closed loop circuit, and the closed loop circuit 13 includes a delay circuit 14, a filter circuit 15, an address generator 16,
It is composed of a drive waveform memory 17, a multiplier 11, and an adder 18. The address generator 16 generates an address for the drive waveform memory 17 based on the address information from the CPU 7, and the drive waveform memory 17 generates a predetermined drive waveform for musical tone synthesis in accordance with the generated address, and the multiplier generates a predetermined drive waveform for musical tone synthesis. 11. Note that the address generator 16 may be of a type that generates addresses by referring to a table. Multiplier 11 is drive waveform memory 1
7 is multiplied by the output signal of bandpass filter 8 and the result is output to adder 18 . The adder 18, together with the delay circuit 14 and the filter circuit 15, forms a closed loop circuit for the output signal from the multiplier 11, and feeds back the drive waveform to synthesize musical tones. That is, the filter circuit 15 includes a low-pass filter and simulates the vibration loss of the string, and the delay circuit 14 simulates the propagation delay of vibration in the string. In this case, in this embodiment, the delay characteristic in the delay circuit 14 can be changed based on the delay signal DL from the CPU 7. Note that instead of the multiplier 11, for example, an adder 11X may be used. In the case of multiplication, AM modulation type control can be realized, and in the case of addition, noise superposition type control can be realized.

The output taken out from the closed loop circuit 13 is supplied to a multiplier 19, and the multiplier 19 multiplies this output signal by the envelope signal from the 0-bus filter 4 and outputs the result to a mixer amplifier 20. This allows the performer to synchronize the envelope of the synthesized musical tone with the envelope of the electric guitar 1. The mixer amplifier 20 mixes the raw signal of the electric guitar 1 and the signal from the multiplier 19 via the interface 2 at a predetermined ratio and amplifies the mixer to drive the speaker 21 .

Next, we will discuss the operation of the embodiment with the above-mentioned configuration in the second section.
This will be explained with reference to the flowchart shown in the figure.

First, in step S1, electric guitar 1, which is an external controller,
Determine whether or not a rising pulse from
It waits in this step and does nothing until a rising pulse is detected. When a rising pulse is detected, the musical tone currently being generated is dumped in step S2 to prepare for the next tone. Next, in step S3, the pitch of the output musical tone is detected, and in step S4, the delay length DL is calculated based on the detected pitch and is output to the delay circuit 14. As a result, the delay characteristics in the delay circuit 14 are changed, and as a result, the simulation characteristics of the string vibration propagation delay in the closed loop circuit 13 are changed.

Note that pitch detection is performed by the pitch extraction circuit 5 using hardware, but is not limited to this; the detection of the pitch is performed by software processing.
You can also detect it yourself. Further, in calculating the delay length DL, a table may be provided in the ROM 9 and referred to.

Here, the closed loop circuit 13, which is a so-called musical tone synthesis block, is a circuit that can synthesize musical tones by itself.
To synthesize a musical tone, it is necessary to obtain at least pitch information of the output musical tone, so in this embodiment, the output of the electric guitar 1 is analyzed and this is provided to the musical tone synthesis block. Also,
Since the timing of outputting musical tones also needs to be synchronized with the operator, the rising edge of the output of the electric guitar 1 is similarly detected and becomes one of the start information for musical tone synthesis.

Next, in step S5, the start address of the drive waveform memory 17 is obtained according to the pitch of the output musical tone, and in step S6, the characteristics of the bandpass filter 8 are determined according to this pitch and information from the operation panel 12. Finally, a start signal is sent to the address generator 17 in step S7. As a result, musical tone synthesis is automatically started.

As described above, in this embodiment, the reflection of the operator information on the synthesized musical tone is realized by directly multiplying the drive waveform by the output of the electric guitar 1 passed through the band pass filter 8. At this time, for example, if the characteristics of the band-pass filter 8 are extremely low-pass, the output characteristics of the band-pass filter 8 become an envelope itself, and an envelope can be applied to the synthesized waveform of the musical tone. In this case, it is desirable that the calculation with the signal generated by the drive waveform memory 17 be multiplication.

On the other hand, when the characteristics of the bandpass filter 8 are in the overtone range, modulation can be applied to the musical tone synthesis system according to the degree of overtone inclusion in the musical tone output from the electric guitar 1. In this case, the calculation may be performed by addition to achieve an effect of adding a high frequency noise-like component to the drive waveform. As a result, when the actual waveform contains many high-frequency components, the synthesized musical tone also contains many high-frequency components, and when there are few, the high-frequency components are reduced.

With the above operations, taking into account the input of performance information,
It is possible to reflect subtle expressions of the musical tone of the electric guitar 1 by the performer. In addition, we use controls that can express the performer's subtle sensations with respect to the sound source consisting of delay and filter feedback, and this signal information is given to the sound source, allowing the performer to express detailed control. At the same time, by adding a noise-like component through subtle control, it is possible to spread the frequency components of the output musical tone.

Now, further considering the characteristics of the bandpass filter 8, this characteristic needs to have at least a correlation with the pitch of the output of the electric guitar 1. For example, completely unrelated controls are possible, but they are of little significance in terms of effective control of musical tones. Furthermore, as described above, this characteristic is also given by the operation panel 12, so for example, by operating the operation panel 12, the center frequency of the bandpass filter 8 can be selected to impart an envelope-like effect to the musical tone as described above. It is also possible to specify whether to add a modulating effect or to add a modulating effect. Note that this may be done by changing the bandwidth of the pantone filter 8.

Next, the present invention is not limited to the above embodiments, and various modifications as described below are possible.

(I) In this embodiment, the envelope of the original guitar sound is multiplied and then mixed with the original sound and output, but this is not the only option.
It may be converted into A and output.

(If) In this embodiment, it has been shown that the synthesized waveform is modulated based on the output musical tone of a guitar, but other musical instruments (keyboard instruments, etc.) may be used.

(III) Musical sound control data is not limited to the musical sound waveform itself of any musical instrument, but may also be the aftertouch of ordinary electronic musical instruments as long as it is given in a natural form by the performer.

(IV) In this embodiment, only modulation by multiplication and modulation by addition are shown, but frequency modulation may be applied by modulating address information, for example.

(V) Although implementation by hardware is shown, pitch detection, rising edge detection, etc. may be performed by software processing by a CPU.

(Vl) The part performed by software processing by the CPU may be implemented by replacing it with hardware.

(■) Alternatively, the configuration shown in FIG. 1 may be provided for each string to support multiple sound productions. In this case, it goes without saying that the sound sources may be effectively utilized by time division multiplexing or channel assignment.

"Effects of the Invention" According to the present invention, since input of performance information is taken into consideration,
It is possible to reflect the subtle expressions of musical tones of musical instruments by the performer, and it is possible to output the musical tones desired by the performer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a flowchart of tone synthesis control in the embodiment. 1... Electric guitar, 3... Output information detection circuit 10... Control means, 13... Closed loop circuit. (output information detection means),

Claims (1)

[Claims] A sounding body, a sounding operator that simultaneously excites a part of the sounding body and generates vibrations that propagate back and forth through the sounding body, a low-pass filter that simulates vibration loss of the sounding body, and A musical tone synthesis device comprising a musical tone forming section including a closed loop circuit in which a delay circuit for simulating a propagation delay of vibrations in a sounding body is connected in a closed loop, an output information detection means for detecting output information of the sound generation operator; , and a control means for generating a control signal that changes the characteristics of musical tone synthesis based on the output of the output information detecting means, and the closed loop circuit generates a control signal that changes the characteristics of musical tone synthesis based on the control signal from the control means. A musical tone synthesis device characterized in that it is configured to synthesize musical tones.