Patent Application
20130025436
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2011-164299, filed Jul. 27, 2011, the entire contents of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a musical sound producing apparatus, a recording medium, and a musical sound producing method by which the sound producing mechanism of a drawbar-type electronic organ is simulated.
2. Description of the Related Art
In a drawbar-type electronic organ (hereinafter referred to as a drawbar organ), a musical sound of a desired tone is created by nine types of sine waves having different pitches being arbitrarily combined and synthesized based on operations of nine types of drawbars indicating different footage (“16′ (′ is a symbol indicating feet)”, “5 and ⅓′”, “8′”, “4′”, “2 and ⅔′”, “2′”, “1 and ⅗′”, “1 and ⅓′”, and “1′”).
When “16′” of the drawbars is a fundamental, “5 and ⅓′” is a note that is one octave and a fifth above the fundamental, “8′” is a note that is one octave above the fundamental (second harmonic), “4” is a note that is two octaves above the fundamental (fourth harmonic), “2 and ⅔” is a note that is two octaves and a fifth above the fundamental, “2′” is a note that is three octaves above the fundamental (eighth harmonic), “1 and ⅗′” is a note that is three octaves and a third above the fundamental, “1 and ⅓′” is a note that is three octaves and a fifth above the fundamental, and “1” is a note that is four octaves above the fundamental (sixteenth harmonic).
In recent years, an electronic musical instrument has become known that produces musical sounds similar in tone to that of a drawbar organ in accordance with a sine wave additive synthesis algorithm using a waveform data readout-type sound source. For example, Japanese Patent Application Laid-open (Kokai) Publication No. 2000-259157 discloses this type of technique.
In drawbar organs, each key of the keyboard is provided with switches that control the production and muting of sound per footage, and a unique musical sound referred to as a so-called drawbar sound is created by the behavior of the switches respectively provided for each footage which are turned ON and OFF in response to key depression and release operations. However, all that is achieved in the technique disclosed in Japanese Patent Application Laid-open (Kokai) Publication No. 2000-259157 is that a fundamental and a plurality of harmonics generated based on drawbar operations are synthesized by sine-wave synthesis, and therefore there is a problem in that a unique drawbar sound such as that generated by the sound producing mechanism of an actual drawbar organ cannot be generated.
The present invention has been conceived in light of the above-described problem, and an object of the present invention is to provide a musical sound producing apparatus, a recording medium, and a musical sound producing method by which a unique drawbar sound such as that generated by the sound producing mechanism of an actual drawbar organ can be generated.
In order to achieve the above-described object, in accordance with one aspect of the present invention, there is provided a musical sound producing apparatus comprising: sound source which produces a fundamental and a plurality of harmonics of a musical sound; a sound production timing generating section which generates sound production timings of the fundamental and the plurality of harmonics to be produced by the sound source, based on a key depression operation; a sound production instructing section which instructs the sound source to produce the fundamental and the plurality of harmonics based on the sound production timings generated by the sound production timing generating section; a key release speed acquiring section which acquires a key release speed in response to a key release operation; a muting timing changing section which changes muting timings of the fundamental and the plurality of harmonics produced by the sound source, based on the key release speed acquired by the key release speed acquiring section; and a muting instructing section which instructs the sound source to mute the fundamental and the plurality of harmonics based on the muting timings changed by the muting timing changing section.
In accordance with another aspect of the present invention, there is provided a non-transitory computer-readable storage medium having stored thereon a program that is executable by a computer used in a musical sound producing apparatus, the program being executable by the computer to perform functions comprising: sound production timing generation processing for generating sound production timings of a fundamental and a plurality of harmonics of a musical sound to be produced by a sound source, based on a key depression operation; sound production instruction processing for instructing the sound source to produce the fundamental and the plurality of harmonics based on the sound production timings generated by the sound production timing generation processing; key release speed acquisition processing for acquiring a key release speed in response to a key release operation; muting timing change processing for changing muting timings of the fundamental and the plurality of harmonics produced by the sound source, based on the key release speed acquired by the key release speed acquisition processing; and muting instruction processing for instructing the sound source to mute the fundamental and the plurality of harmonics based on the muting timings changed by the muting timing change processing.
In accordance with another aspect of the present invention, there is provided a musical sound producing method used for a musical sound producing apparatus comprising: a sound production timing generating step of generating sound production timings of a fundamental and a plurality of harmonics of a musical sound to be produced by a sound source, based on a key depression operation; a sound production instructing step of instructing the sound source to produce the fundamental and the plurality of harmonics based on the sound production timings generated in the sound production timing generating step; a key release speed acquiring step of acquiring a key release speed in response to a key release operation; a muting timing changing step of changing muting timings of the fundamental and the plurality of harmonics produced by the sound source, based on the key release speed acquired by the key release speed acquiring step; and a muting instructing step of instructing the sound source to mute the fundamental and the plurality of harmonics based on the muting timings changed in the muting timing changing step.
The above and further objects and novel features of the present invention will more fully appear from the following detailed description when the same is read in conjunction with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the invention.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the present invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the present invention in which:
An embodiment of the present invention will hereinafter be described with reference to the drawings.
A. Overview of the Invention
In a drawbar organ, each key of the keyboard is provided with switches that control the production and muting of sound per footage. These switches respectively provided for each footage are not to be simultaneously turned ON in response to key depression, but to be turned ON at different timings. That is, the production timings of fundamental and harmonic components that are synthesized by additive synthesis vary from one another, whereby slight tone changes occur at the start of sound production. These tone changes which occur during a key depression are dependent on the key depression velocity (key depression speed). That is, when the key depression speed is fast, the variations in the production timings of the fundamental and harmonic components decrease, and whereby the tone changes decrease. Conversely, when the key depression speed is slow, the variations in the production timings of the fundamental and harmonic components increase, and whereby the tone changes increase.
Such tone changes also occur during key release. That is, timings at which the switches respectively provided for each footage are turned OFF in response to key release vary from one another, whereby the stop timings of the fundamental and harmonic components that are synthesized by additive synthesis differ from one another, and slight tone changes occur at the start of muting. These tone changes differ depending on the key release velocity (key release speed). That is, when the key is quickly released, the variations in the stop timings of the harmonic components decrease, and whereby the tone changes decrease. Conversely, when the key is slowly released, the variations in the stop timings of the harmonic components increase, and whereby the tone changes increase.
In an actual drawbar organ, the switches provided in each key of the keyboard for each footage constitute multiple row contacts, and therefore an order in which these switches are turned ON during key depression differs from an order in which they are turned OFF during key release. Accordingly, tone changes occurred during the key depression differ from tone changes occurred during the key release. In addition, as a result of these switches being turned ON and OFF in response to key depression and release operations, chattering noise occurs and mixes with produced musical sounds as click sounds (key clicks). In the present invention, the sound producing mechanism of a drawbar organ based on the above-described series of observations is simulated by operations (key depression processing and key release processing described hereafter) of a central processing unit (CPU), whereby a unique drawbar sound such as that generated by the sound producing mechanism of an actual drawbar organ is generated.
B. Structure
Next, the structure of a musical sound producing apparatus 100 according to the embodiment of the present invention will be described with reference to
The drawbar 11 includes slide volume controllers 11a-1 to 11a-9 and an analog-to-digital (A/D) converter 11b, as shown in the example in
The slide volume controllers 11a-1 to 11a-9 are respectively assigned “16′ (′ is a symbol indicating feet)” that is a fundamental, “5 and ⅓′” that is one octave and a fifth above the fundamental, “8′” that is one octave above the fundamental (second harmonic), “4” that is two octaves above the fundamental (fourth harmonic), “2 and ⅔′” that is two octaves and a fifth above the fundamental, “2′” that is three octaves above the fundamental (eighth harmonic), “1 and ⅗” that is three octaves and a third above the fundamental, “1 and ⅓′” that is three octaves and a fifth above the fundamental, and “1′” that is four octaves above the fundamental (sixteenth harmonic).
The CPU 12 runs various programs stored in a read-only memory (ROM) 13, and controls the sound source 15 to create musical sounds based on musical performance information generated in response to the key depression and release operations (play operations) of the keyboard 10. The characteristic processing operations of the CPU 12 related to the scope of the present invention will be described hereafter. The ROM 13 stores various programs that are loaded into the CPU 12. The various programs herein include the main routine, key depression processing, and key release processing described hereafter. The RAM 14 includes a work area and a data area.
The work area of the RAM 14 temporarily stores various register and flag data that are used for processing by the CPU 12. Specifically, the drawbar outputs Ddr (ch1) to Ddr (ch9) generated by the drawbar 11 are temporarily stored in the work area of the RAM 14, under the control of the CPU 12. The data area of the RAM 14 stores plural types of click sound volume Cv associated with, for example, various types of velocities. Among the plural types of click sound volume Cv, click sound volume Cv corresponding to the velocity VEL of key depression (or the velocity VEL1 of key release) is read out by the CPU 12.
As shown in
The oscillator 15a-10 generates click waveform data equivalent to chattering noise that occurs during key depression and release operations. Specifically, the oscillator 15a-10 stores plural types of click waveform data associated with various types of velocities, and replays and outputs click waveform data of a waveform type selected therefrom by the CPU 12 based on the velocity of key depression (or key release). Note that a method can also be used in which click waveform data is generated by the filtering of noise waveforms and pulse waveforms, in addition to the waveform data readout method described above.
The coefficient multipliers 15b-1 to 15b-9 respectively multiply sine waveform data outputted from the oscillators 15a-1 to 15a-9 by the corresponding drawbar outputs Ddr (ch1) to Ddr (ch9), and output the sine waveform data of the fundamental and the plurality of harmonics whose levels have been controlled. These drawbar outputs Ddr (ch1) to Ddr (ch9) serving as the multiplier coefficients are read out from the work area of the RAM 14 by the CPU 12. The coefficient multiplier 15b-10 multiplies an output of the oscillator 15a-10 by the click sound volume Cv, and outputs click waveform data whose level has been controlled. The click sound volume Cv serving as the multiplier coefficient is selected and read out from the data area of the RAM 14 by the CPU 12 based on the velocity of key depression (or key release).
The adder 15c performs additive synthesis of the sine waveform data of the fundamental and the plurality of harmonics outputted from the coefficient multipliers 15b-1 to 15b-9, and adds thereto level-controlled click waveform data outputted from the coefficient multiplier 15b-10. As a result, sine wave synthesized waveform data in which click sound has been mixed is generated. The rotary effector 15d adds a rotary effect for mimicking the sound of an actual drawbar organ, or in other words, a unique modulation effect created by two rotating speakers (a rotor and a horn) to sine wave synthesized waveform data in which click sound has been mixed, and thereby generates musical sound waveform data “wave”. A sound system 16 converts musical sound waveform data “wave” outputted from the sound source 16 to analog signal format, and after performing the elimination of unnecessary noise and level amplification, outputs the sound from a speaker.
C. Operations
Next, operations of the embodiment structured as above will be described with reference to
(1) Operations in the Main Routine
When the musical sound producing apparatus 100 is turned ON, the CPU 12 proceeds to Step SA1 shown in
Next, at Step SA3, the CPU 12 performs key depression processing. In this key depression processing, the production timings of fundamental and harmonic components respectively corresponding to each footage are changed to vary from one another in accordance with wait time “TIME” that changes based on key depression speed, whereby the sine waveform data of the fundamental and harmonic components to be synthesized by additive synthesis are changed to differ from one another, as described in detail later. As a result, slight tone changes that occur at the start of sound production in an actual drawbar organ are simulated in that, when the key depression speed is fast, the variations in the production timings of the fundamental and harmonic components decrease and the tone changes decrease, and when the key depression speed is slow, the variations in the production timings of the fundamental and harmonic components increase and the tone changes increase. In addition, a click sound whose waveform type and sound volume correspond to the key depression velocity VEL is generated, and mixed with the drawbar sound in which the slight tone changes occur when the sound is produced.
Next, at Step SA4, the CPU 12 performs key release processing. In this key release processing, the stop timings of the fundamental and harmonic components respectively corresponding to each footage are changed to vary from one another in accordance with wait time “TIME1” that changes based on key release speed, whereby the sine waveform data of the fundamental and harmonic components to be muted are changed to differ from one another, as described in detail later. As a result, slight tone changes that occur at the start of muting in an actual drawbar organ are simulated in that, when the key release speed is fast, the variations in the stop timings of the fundamental and harmonic components decrease and the tone changes decrease, and when the key release speed is slow, the variations in the stop timings of the fundamental and harmonic components increase and the tone changes increase. In addition, a click sound whose waveform type and sound volume correspond to the key release velocity VEL1 is generated, and mixed with the drawbar sound in which the slight tone changes occur when the sound is muted.
Then, when the key release processing at Step SA4 is completed, the CPU 12 returns to Step SA2, and hereafter repeats Step SA2 to Step SA4 described above until the power is turned OFF, whereby unique drawbar sounds such as those generated by the sound producing mechanism of an actual drawbar organ are generated.
(2) Operations in the Key Depression Processing
Next, the operations in the key depression processing will be described with reference to
Next, at Step SB3, the CPU 12 instructs the oscillator 15a-10 of the sound source 15 to replay click waveform data whose type corresponds to the key depression velocity VEL. In addition, the CPU 12 reads out click sound volume Cv corresponding to the key depression velocity VEL from the data area of the RAM 14, and supplies it to the coefficient multiplier 15b-10 as a multiplier coefficient. As a result, a click sound whose type and sound volume correspond to the key depression velocity VEL is generated.
Then, the CPU 12 proceeds to Step SB4 and instructs the sound source 15 to produce the sound of the sine waveform data of a harmonic component corresponding to “1” (sixteenth harmonic). As a result, the sine waveform data of the harmonic component (sixteenth harmonic) corresponding to “1′”, which is sine waveform data read out from the oscillator 15a-9 at a readout speed based on the key number (pitch) of the depressed key and multiplied by the drawbar output Ddr (ch9), is generated.
Next, the CPU 12 performs WAIT processing shown in
Then, when the wait time “TIME” has elapsed, the CPU 12 proceeds to Step SB6 and instructs the sound source 15 to produce the sound of the sine waveform data of a harmonic component corresponding to “1 and ⅓”. As a result, the sine waveform data of the harmonic component corresponding to “1 and ⅓”, which is sine waveform data read out from the oscillator 15a-8 at a readout speed based on the key number (pitch) of the depressed key and multiplied by the drawbar output Ddr (ch8), is generated. Subsequently, the CPU 12 performs the WAIT processing at Step SB7, and waits until the wait time “TIME” calculated from the inverse of the key depression velocity VEL has elapsed.
At subsequent Step SB8 to Step SB9, similarly, the CPU 12 generates the sine waveform data of a harmonic component corresponding to “1 and ⅗′” whose level has been controlled based on the drawbar output Ddr (ch7), and waits until the wait time “TIME” calculated from the inverse of the key depression velocity VEL has elapsed. Next, at Step SB10 to Step SB11, the CPU 12 generates the sine waveform data of a harmonic component corresponding to “2′” (eighth harmonic) whose level has been controlled based on the drawbar output Ddr (ch6), and waits until the wait time “TIME” calculated from the inverse of the key depression velocity VEL has elapsed.
Next, at Step SB12 to Step SB13, the CPU 12 generates the sine waveform data of a harmonic component corresponding to “2 and ⅔” whose level has been controlled based on the drawbar output Ddr (ch5), and waits until the wait time “TIME” calculated from the inverse of the key depression velocity VEL has elapsed. Next, at Step SB14 to Step SB15, the CPU 12 generates the sine waveform data of a harmonic component corresponding to “4′” (fourth harmonic) whose level has been controlled based on the drawbar output Ddr (ch4), and waits until the wait time “TIME” calculated from the inverse of the key depression velocity VEL has elapsed.
Next, at Step SB16 to Step SB17, the CPU 12 generates the sine waveform data of a harmonic component corresponding to “8′” (second harmonic) whose level has been controlled based on the drawbar output Ddr (ch3), and waits until the wait time “TIME” calculated from the inverse of the key depression velocity VEL has elapsed. Next, at Step SB18 to Step SB19, the CPU 12 generates the sine waveform data of a harmonic component corresponding to “5 and ⅓” whose level has been controlled based on the drawbar output Ddr (ch2), and waits until the wait time “TIME” calculated from the key depression velocity VEL has elapsed. Then, at Step SB20, the CPU 12 generates the sine waveform data of a fundamental corresponding to “16′” whose level has been controlled based on the drawbar output Ddr (ch1), and ends the key depression processing.
As described above, in the key depression processing, the production timings of fundamental and harmonic components respectively corresponding to each footage are changed to vary from one another in accordance with the wait time “TIME” that changes based on key depression speed, whereby the sine waveform data of the fundamental and harmonic components to be synthesized by additive synthesis are changed to differ from one another. As a result, slight tone changes that occur at the start of sound production in an actual drawbar organ are simulated in that, when the key depression speed is fast, the variations in the production timings of the fundamental and harmonic components decrease and the tone changes decrease, and when the key depression speed is slow, the variations in the production timings of the fundamental and harmonic components increase and the tone changes increase. In addition, a click sound whose waveform type and sound volume correspond to the key depression velocity VEL is generated and mixed with the drawbar sound in which the slight tone changes occur at the start of sound production. Therefore, performance expression more similar to that of an actual drawbar organ is realized.
(3) Operations in the Key Release Processing
Next, the operations in the key release processing will be described with reference to
Next, at Step SD3, the CPU 12 instructs the oscillator 15a-10 of the sound source 15 to replay click waveform data whose type corresponds to the key release velocity VEL1. In addition, the CPU 12 reads out click sound volume Cv corresponds to the key release velocity VEL1 from the data area of the RAM 14, and supplies it to the coefficient multiplier 15b-10 as a multiplier coefficient. As a result, a click sound whose type and sound volume correspond to the key release velocity VEL1 is generated.
Then, the CPU 12 proceeds to Step SD4 and instructs the sound source 15 to mute the sound of the sine waveform data of the fundamental corresponding to “16” and stops waveform output from the oscillator 15a-1. Next, the CPU 12 performs the WAIT processing shown in
Then, when the wait time “TIME1” has elapsed, the CPU 12 proceeds to Step SC6, instructs the sound source 15 to mute the sound of the side waveform data of the harmonic component corresponding to “5 and ⅓′”, and stops waveform output from the oscillator 15a-2. At subsequent Step SD7, the CPU 12 performs the WAIT processing and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed.
At subsequent Step SD8 to Step SD9, similarly, the CPU 12 stops the waveform output of the sine waveform data of the second harmonic corresponding to “8” and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed. Next, at Step SD10 to Step SD11, the CPU 12 stops the waveform output of the sine waveform data of the fourth harmonic corresponding to “4′” and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed. Next, at Step SD12 to Step SD13, the CPU 12 stops the waveform output of the sine waveform data of the harmonic component corresponding to “2 and ⅔′” and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed.
Next, at Step SD14 to Step SD15, the CPU 12 stops the waveform output of the sine waveform data of the eighth harmonic corresponding to “2” and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed. Next, at Step SD16 to Step SD17, the CPU 12 stops the waveform output of the sine waveform data of the harmonic component corresponding to “1 and ⅗′” and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed. Next, at Step SD18 to Step SD19, the CPU 12 stops the waveform output of the sine waveform data of the harmonic component corresponding to “1 and ⅓′” and waits until the wait time “TIME1” calculated from the inverse of the key release velocity VEL1 has elapsed. Then, at Step SD20, the CPU 12 stops the waveform output of the sine waveform data of the sixteenth harmonic corresponding to “1′” and ends the key release processing.
As described above, in the key release processing, the stop timings of the fundamental and harmonic components respectively corresponding to each footage are changed to vary from one another in accordance with the wait time “TIME1” that changes based on key release speed, whereby the sine waveform data of the fundamental and harmonic components to be muted are changed to differ from one another. As a result, slight tone changes that occur at the start of muting in an actual drawbar organ are simulated in that, when the key release speed is fast, the variations in the stop timings of the fundamental and harmonic components decrease and the tone changes decrease, and when the key release speed is slow, the variations in the stop timings of the fundamental and harmonic components increase and the tone changes increase. In addition, a click sound whose waveform type and sound volume correspond to the key release velocity VEL1 is generated and mixed with the drawbar sound in which the slight tone changes occur at the start of muting. Therefore, performance expression more similar to that of an actual drawbar organ is realized.
As described above, in the present embodiment, key depression speed corresponding to a key depression operation is detected, and a click sound whose waveform type and sound volume correspond to the detected key depression speed is generated. In addition, the production timings of the fundamental and harmonic components respectively corresponding to each footage are changed to vary from one another in accordance with wait time “TIME” that changes based on the key depression speed, whereby the sine waveform data of the fundamental and harmonic components to be synthesized by additive synthesis are changed to differ from one another. Also, key release speed based on a key release operation is detected, and a click sound whose waveform type and sound volume correspond to the detected key release speed is generated. In addition, the stop timings of the fundamental and the harmonic components respectively corresponding to each footage are changed to vary from one another in accordance with wait time “TIME1” that changes based on the key release speed, whereby the sine waveform data of the fundamental and the harmonic components to be muted are changed to differ from one another. Accordingly, by the click sound being mixed with the drawbar sound in which the slight tone changes occur at the start of sound production (or at the start of muting), a drawbar sound having performance expression equivalent to that of an actual drawbar organ are generated. That is, a unique drawbar sound such as that generated by the sound producing mechanism of an actual drawbar organ is generated.
In the above-described embodiment, the production timings (or stop timings) of fundamental and harmonic components respectively corresponding to each footage are sequentially changed to vary from one another in accordance with a certain amount of wait time “TIME” (or “TIME1”) calculated as the inverse 1/VEL (or 1/VEL1) of key depression speed (or key release speed). However, the present invention is not limited thereto, and a configuration may be adopted in which, every time a wait time that randomly changes has elapsed, the production of a fundamental and a plurality of harmonics is randomly specified, whereby the production timings of the fundamental and the plurality of harmonics vary from one another. As a result, slight tone changes during key depression (or key release) which occur every time key depression and release operations are performed can be varied for each key depression or release operation.
In addition, in the present embodiment, a click sound whose waveform type and sound volume correspond to key depression speed (or key release speed) is generated. However, a configuration may be adopted in which the waveform type and sound volume of a click sound are randomly varied based on key depression speed (or key release speed). As a result, a sound more similar to the drawbar sound can be created.
While the present invention has been described with reference to the preferred embodiments, it is intended that the invention be not limited by any of the details of the description therein but includes all the embodiments which fall within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-164299 | Jul 2011 | JP | national |
