Electronic musical instrument with effect control dependent on expression and keyboard manipulation
United States Patent 3881387
Tone signals delivered from a tone source section are passed through a variable amplifier for amplitude modification and a variable filter for frequency spectrum modification. A vibrato signal generator, a tremolo signal generator and a filter control signal generator are respectively connected to the tone source section, the variable amplifier and the variable filter for respective controls. The generators are controlled by manual controls in a control pannel section. An expression control provides a voltage representing the expression state and a keyboard provides a voltage representing the depressed key. There voltages are applied via polarity selectors to the respective generators for automatic control dependent on the expression and the keyboard manipulation.
US Patent References:
Multiple vibrato system
Wayne, Jr. - November 1961 - 3007361
Electrical musical instruments
Peterson - April 1967 - 3316341
Vibrato and tremolo system
Jacob - November 1968 - 3413403
RANDOMLY-PERTURBED,LOCKED-WAVE GENERATOR
Martin et al. - November 1969 - 3479440
MANUAL OR KNEE OPERABLE EFFECT SELECTOR SYSTEM IN ELECTRONIC MUSICAL INSTRUMENT
Hoshino - March 1970 - 3499094
Multiple vibrato system
Wayne, Jr. - November 1961 - 3007361
Electrical musical instruments
Peterson - April 1967 - 3316341
Vibrato and tremolo system
Jacob - November 1968 - 3413403
RANDOMLY-PERTURBED,LOCKED-WAVE GENERATOR
Martin et al. - November 1969 - 3479440
MANUAL OR KNEE OPERABLE EFFECT SELECTOR SYSTEM IN ELECTRONIC MUSICAL INSTRUMENT
Hoshino - March 1970 - 3499094
Application Number:
05/441996
Publication Date:
05/06/1975
Filing Date:
02/13/1974
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
84/706, 984/377, 84/705
International Classes:
G10H5/00; G10H5/02; G10H1/02
Field of Search:
84/1.01,1.09-1.11,1.19,1.24,1.25,1.27,DIG.4,DIG.5
US Patent References:
| 3510565 | ELECTRONIC ORGAN WITH MUSICAL NOTES COMPRISING BEAT FREQUENCIES OF A REFERENCE GENERATOR AND NOTE GENERATORS UTILIZING MAGNETOSTRICTIVE OSCILLATORS | May 1970 | Morez | |
| 3553338 | MUSIC AMPLIFIER WITH TONE MODIFYING STAGE | January 1971 | Holman | |
| 3626078 | COMBINATION OF MUSICAL EFFECT SYSTEM AND KNEE CONTROL | December 1971 | Sekiguchi | |
| 3647928 | ELECTRICAL MUSICAL INSTRUMENT WITH ENSEMBLE AND CHIEF EFFECTS AND UNEQUAL STEREOPHONIC OUTPUTS | March 1972 | Turner | |
| 3715447 | ELECTRONIC MUSICAL INSTRUMENT WITH A KEYBOARD DEVICE CAPABLE OF PRODUCING SPECIAL MUSICAL EFFECTS UPON KEY DEPRESSION | February 1973 | Ohno | |
| 3762265 | ELECTRONIC MUSICAL INSTRUMENT HAVING TONE START PROMINENCE CIRCUIT | October 1973 | Adachi | |
| 3819843 | KEYBOARD ELECTRONIC MUSIC INSTRUMENT WITH STEP-WISE VARIABLE VOLUME CONTROL RESPONSIVE TO KEY-TOUCH | June 1974 | Okamoto | |
| 3828110 | CONTROL CIRCUITRY FOR ELECTRONIC MUSICAL INSTRUMENT | August 1974 | Colin | |
| 3835237 | ELECTRONIC MUSICAL INSTRUMENT WITH KEY-DEPENDENT TIME-VARIABLE DELAYING DEVICE | September 1974 | Adachi | |
| 3840690 | ELECTRONIC MUSICAL INSTRUMENT WITH SINGLE KEYBOARD PROVIDING SOUNDS AND EFFECTS | October 1974 | Davoli |
Primary Examiner:
Hartary, Joseph W.
Assistant Examiner:
Witkowski, Stanley J.
Attorney, Agent or Firm:
Burns, Robert Lobato Emmanuel Adams Bruce E. J. L.
Claims:
I claim
1. An electronic musical instrument which comprises:
2. An electronic musical instrument which comprises:
3. An electronic musical instrument as claimed in claim 2 in which said control panel section comprises control circuits for producing said first control voltages, and said expression-keyboard controlled section comprises polarity control circuits for developing said second control voltages; a mixer circuit for mixing outputs from said expression device and keyboard; and switching means for selectively applying an output from the mixer circuit to selected ones of the polarity control circuits.
4. An electronic musical instrument as claimed in claim 3 in which each of said polarity control circuits is provided with a variable resistor having a sliding contact and having one end directly connected to said switching means and its other end connected through an inverter to said switching means so that the polarity and value of said control voltage output from said polarity control circuit is developed by adjusting the position of a sliding contact of the variable resistor.
1. An electronic musical instrument which comprises:
2. An electronic musical instrument which comprises:
3. An electronic musical instrument as claimed in claim 2 in which said control panel section comprises control circuits for producing said first control voltages, and said expression-keyboard controlled section comprises polarity control circuits for developing said second control voltages; a mixer circuit for mixing outputs from said expression device and keyboard; and switching means for selectively applying an output from the mixer circuit to selected ones of the polarity control circuits.
4. An electronic musical instrument as claimed in claim 3 in which each of said polarity control circuits is provided with a variable resistor having a sliding contact and having one end directly connected to said switching means and its other end connected through an inverter to said switching means so that the polarity and value of said control voltage output from said polarity control circuit is developed by adjusting the position of a sliding contact of the variable resistor.
Description:
BACKGROUND OF THE INVENTION
This invention relates to electronic musical instruments in which tonal effects such as a vibrato effect and a tremolo effect can be added to musical tones as desired by the performer.
It is known that while playing a natural musical instrument, the performer plays the instrument in such a manner that the frequency and depth (or amplitude) of vibrato and tremolo increase with the sound level of musical tones and in this playing harmonic components included in the musical tones is reduced. Furthermore, it is known that he plays the instrument in such a manner that the frequency and depth of vibrato increase as the playing tone region becomes higher and in this playing also the harmonic components included in the musical tones becomes less.
Therefore, in the case when an electronic organ is played, if the electronic organ is so designed that substantially the same effects as those added in the playing of the natural musical instrument are added in the playing of the electronic organ, the playing of the electronic organ will have the same effects in tonal quality as those in the playing of the natural musical instrument. Furthermore, with the electronic organ, there is a demand for the addition of the effects opposite to those added in the playing of the natural musical instrument.
SUMMARY OF THE INVENTION
Accordingly, a primary object of this invention is to provide an electronic musical instrument in which two contradictory demands for the addition of tonal effects in the playing thereof are satisfied, that is, not only a demand for adding the same tonal effects as those in the playing of a natural musical instrument but also a demand for adding the opposite tonal effects in the playing are satisfied.
Another object of the invention is to provide an electronic musical instrument in which kinds and qualities of tonal effects can be readily selected and combined as desired by the performer whereby he can express musical effects intended by him in the performance.
The manner in which the foregoing objects and other objects are achieved by this invention will become more apparent from the following detailed description and the appended claims when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram illustrating one example of an electronic musical instrument according to this invention; and
FIG. 2 is a graphical representation indicating the characteristic curves of a variable filter shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, there is shown one example of an electronic musical instrument according to this invention in which a vibrato effect, a tremolo effect and a harmonic-component changing effect (hereinafter referred to as "a filter effect") can be attained.
This electronic musical instrument comprises a tone source section 1 including conventional master oscillators, frequency dividers and tone keyers, a vibrato signal generator 2 for producing a vibrato signal V B which controls the master oscillators, a voltage-controlled type variable amplifier 3 for amplitude-modulating tone signal outputs from the tone source section 1 by a tremolo signal V R from a tremolo signal generator 4, and a voltage-controlled type variable filter 6 whose frequency characteristic is changed by a filter controlling signal V F from a filter control signal generator 7.
The tone signal output from the tone source section 1 is frequency-modulated by the vibrato signal V B from the vibrato signal generator 2, so that the vibrato effect having a vibrato speed and depth which are determined by the frequency and amplitude of the vibrato signal V B can be added to the musical tones. The vibrato signal generator 2 is provided with a voltage-controlled type oscillator 2a and a voltage-controlled type amplifier 2b. The oscillator 2a varies its oscillation frequency in accordance with a vibrato-speed controlling voltage signal V BS described later, while the amplifier 2b amplifies the oscillation output from the oscillator 2a at a variable amplification degree determined by a vibrato-depth controlling voltage signal V BD described later. The oscillation output from the oscillator 2a is sinusoidal.
In the variable amplifier 3, the output from the tone source section 1 is amplitude-modulated by the tremolo signal V R from the tremolo signal generator 4 as was described above, whereby the tremolo effect having a tremolo speed and depth which are determined by the frequency and amplitude of the tremolo signal V R is added to the musical tones. The tremolo signal generator 4 comprises a voltage-controlled type oscillator 4a which is controlled by a tremolo-speed controlling voltage signal V RS described later and a voltage-controlled type amplifier 4b which is controlled by a tremolo-depth controlling voltage signal V RD described later.
The oscillator 4a is provided with a switch 5. When the moving contact of the switch 5 is set at a position 5a the oscillator 4a produces a sinusoidal output, while when the moving contact is set at the other position 5b the oscillator 4a produces a saw-tooth output. One embodiment of the oscillator 4a includes a phase-shift oscillator and a relaxation oscillator. The terminal 5a is connected to the power input of the phase-shift oscillator while the terminal 5b is connected to the power input of the relaxation oscillator. The outputs of both oscillators are connected to the amplifier 4b. Other suitable waveshapes such as square wave and triangular wave can be utilized.
The voltage-controlled type variable filter 6 is connected to the output of the variable amplifier 3 for receiving amplitude modified tone signals. The frequency characteristic of this variable filter 6 is changed by the filter controlling signal V F from the filter control signal generator 7 as was described before, for modifying the frequency spectrum of the tone signals passing therethrough. More specifically, in this example of the invention, the variable filter 6 operates in such a manner that it shows higher frequency region suppressing characteristic as is indicated by a curve I in FIG. 2 when the signal V F is small (low dc voltage), while it shows a higher frequency region emphasizing characteristic as is indicated by a curve II in FIG. 2 when the signal V F is great (high dc voltage). A particularly simple embodiment of the filter 6 comprises a first filter section having the characteristic II, shown in FIG. 2, and a highcut tone control circuit (Shunt-type filter) connected in cascade with the first filter section. The filter control signal generator 7 is an amplifier which amplifies a filter controlling voltage signal V FD described later to form the filter controlling signal V F .
The vibrato signal generator 2, the tremolo signal generator 4 and the filter control signal generator 7 are controlled by output voltages from a control panel section 10 which is provided with manipulating tablets on a panel, and in addition by output voltages from an expression-keyboard controlled section 13 which operates in connection with the manipulation of an expression control device 11 and a keyboard 12 as will be described in detail later. These output voltages are the voltage signals V BD , V BS , V RD , V RS and V FD described before.
The control panel section 10 is provided with a vibrato-depth control circuit 21D, a vibrato-speed control circuit 21S, a tremolo-depth control circuit 22D, a tremolo-speed control circuit 22S and a filter control circuit 23D. Each of these control circuits is constituted, for instance, by a potentiometer connected to a dc power source (not shown) to produce a dc control voltage of, for instance, from 0 volt to 10 volts through the manipulation of the respective tablet.
In the expression control device 11, an expression state representing voltage is produced which varies within the range of, for instance, from 0 volt to 10 volts in accordance with the manipulation angle of the foot pedal of the expression control device 11, while in the keyboard 12, a pitch representing voltage is produced which varies within the range of, for instance, from 0 volt to 10 volts in accordance with the tone pitch of the depressed key in the keyboard 12. These two representative voltages are applied to two ends of a mixing variable resistor 26 provided in a mixer 25. Therefore, the expression state representing voltage and the pitch representing voltage thus applied are mixed through the variable resistor 26, the mixing ratio depending on the position of the sliding contact of the variable resistor 26. Thus, the mixer 25 produces an mixed output voltage of from 0 volt to 10 volts.
The mixed output voltage thus produced is applied through change-over switches 41D, 41S, 42D, 42S and 43D to polarity selector circuits 31D, 31S, 32D, 32S and 33D, respectively, which are provided corresponding to the control circuits 21D, 21S, 22D, 22S and 23D on the panel control section 10, for selecting the polarity and value of the mixed output from the mixer 25.
The selector circuit 31D is provided with a variable resistor k. The mixed output voltage described above is applied directly to one of the terminals of the variable resistor k and to the other terminal through an inverter INV. Therefore, when the sliding contact of the variable resistor k is set at one end (+100%) of the resistor k (hereinafter referred to as a "+100% position") the mixed output voltage is applied to the sliding contact as it is; however, when the sliding contact is positioned at the other end (-100%) (hereinafter referred to as a "-100% position"), the mixed output voltage is applied to the sliding contact with its polarity inverted. Thus, an output voltage from the variable resistor k is 0 volt when the sliding contact is positioned at the center of the resistor k (hereinafter referred to as a "0% position"), a voltage of from 0 volt to +10 volts when the sliding contact is positioned on the +100% position side of the resistor k, and a voltage of from 0 volt to -10 volts when the sliding contact is positioned on the -100% position side of the same. The other selector circuits 31S, 32D, 32S and 33D have the same construction as that of the selector circuit 31D. Each of the selector circuits 31D, 31S, 32D, 32S and 33D is provided with a pilot lamp l which is turned on when the output voltage from the variable resistor k is 0 volt. Such a lamp circuit can be arbitrarily designed by an engineer in this field.
The output terminal of the control circuit 21D on the panel control section 10 and the output terminal of the selector circuit 31D in the expression-keyboard controlled section 13 are connected together, if necessary through resistor r 1 and r 2 , respectively. When the switch 41D in the section 13 is off, that is, the movable contact is thrown to the ground side, an output voltage from the control circuit 21D is applied only, as the vibrato-depth controlling voltage signal V BD , to the amplifier 2b in the vibrato signal generator 2. When the switch 41D is on, an output voltage from the selector circuit 31D is also applied, as the vibrato-depth controlling voltage signal V BD , to the amplifier 2b.
The constructions of the selector circuits 31S, 32D, 32S and 33D and the connections between these selector circuits and the control circuits 21S, 22D, 22S and 23D are the same as that of the selector circuit 31D and that between this selector circuit and the control circuit 21D described above. More specifically, when the switch 41S is off (or on), an output voltage from the control circuit 21S (or also the selector circuit 31S) is applied, as the vibrato-speed controlling voltage signal V BS , to the oscillator 2a in the vibrato signal generator 2. When the switch 42D is off (or on), an output voltage from the control circuit 22D (or also the selecting circuit 32D) is applied, as the tremolo-depth controlling voltage signal V RD , to the amplifier 4b in the tremolo signal generator 4. When the switch 42S is off (or on), an output voltage from the control circuit 22S (or also the selector circuit 32S) is applied, as the tremolo-speed controlling voltage signal V RS , to the oscillator 4a. Furthermore, when the switch 43D is off (or on), an output voltage from the control circuit 23D (or also the selector circuit 33D) is applied, as the filter controlling voltage signal V FD , to the amplifier 7.
With the musical instrument thus organized, the addition of tonal effects to musical tones regardless of the expression and pitch of the musical tones can be achieved as on a conventional musical instrument by setting the poles of the switches 41D, 41S, 42D, 42S and 43D at the off-positions. That is the vibrato depth and speed the tremolo depth and speed and the harmonic components included in the musical tone can be changed as much as desired, by manually controlling the control circuits 21D, 21S, 22D, 22S and 23D respectively through the tablets provided on the panel.
In the case where the tonal effects are to be changed relative to the expression and pitch of musical tones, it can be achieved by closing the switches 41D, 41S, 42D, 42S and 43D. In this operation, if the position of the sliding contact of the variable resistor 26 is adjusted, the vibrato depth and speed, the tremolo depth and speed and the harmonic components included in the musical tone can be changed with the variation in sound volume (expression) which is caused by the manipulation of the expression device 11 and the variation in tone pitch which is caused by selectively depressing the keys on the keyboard 12. In this operation, the degrees of contribution of the expression device 11 and the keyboard 12 to the addition of the tonal effects to the musical notes are determined by the position of the sliding contact of the variable resistor 26.
When the switches 41D through 43D are on, the output voltages from the selector circuits 31D through 33D can be 0 volt, a positive voltage, and a negative voltage respectively as the sliding contact of the variable resistor k is set at the 0% position, the +100% position and the -100% position. In this connection, when the sliding contact is set at the 0% position, the tonal effects such as vibrato effect can no longer be changed by the manipulation of the expression device 11 and keyboard 12. When the sliding contact is set at the +100% position, if musical tones are produced with the manipulation of the expression device 11 and the keyboard 12 in such a manner that the sound volume and pitch are increased, the tonal effects such as a vibrato effect increase also. In contrast, when the sliding contact is set at the -100% position, if the musical tones are produced with the manipulation of the expression device 11 and keyboard 12 in such a manner that the sound volume and pitch are increased, the tonal effects decrease.
When the movable contact of the switch 5 provided in the oscillator 4a is set at the position 5a, a tonal effect such as is similar to the tremolo effect on the vibraphone is imparted to the musical tones. When the pole is thrown to the position 5b, a tonal effect such as is similar to the tremolo effect on the mandolin is imparted to the musical tones.
The switches 41D through 43D should be manipulated without causing the production of unnaturalness in the musical tones being played. For this purpose, the circuit shown in FIG. 1 is so formed that the performer should preferably manipulate the switches only when the pilot lamps L are lighted on. Since the output voltages of the selector circuits 31D through 33D are 0 volt when the pilot lamps L are on, the tonal effect control conditions by the control panel section can be smoothly changed to those by the expression-keyboard controlled section 13 without production of unnaturalness in musical tones.
Thus, according to this invention, an electronic organ in which the depth and speed of vibrato, the depth and speed of tremolo and the harmonic components (spectra) included in musical tones can of course be controlled by the control panel section 10 only regardless of the variation in sound volume and pitch of the musical tones, and in addition the tonal effects dependent on the variation in volume and pitch of the musical tones can also be attained in connection with the expression-keyboard controlled section 13. According to the circuit of FIG. 1, the tonal effect control by the expression-keyboard controlled section 13 can be carried out by selectively combining the tonal effect which becomes deeper and faster with the increase of the volume and pitch and also the opposite tonal effect, and therefore the tonal effects intended by the performer can be satisfactorily practiced by the circuit. Furthermore, these effects can be attained by a simple operation such as the manipulation of the switches and the sliding of the sliding contacts of the variable resistors included in the circuit shown in FIG. 1.
This invention has been described in connection with three tonal effects; vibrato effect, tremolo effect and filter effect; however it can be applied to the case also where a sustain effect, marimba effect or the like are to be added to the musical tones.
This invention relates to electronic musical instruments in which tonal effects such as a vibrato effect and a tremolo effect can be added to musical tones as desired by the performer.
It is known that while playing a natural musical instrument, the performer plays the instrument in such a manner that the frequency and depth (or amplitude) of vibrato and tremolo increase with the sound level of musical tones and in this playing harmonic components included in the musical tones is reduced. Furthermore, it is known that he plays the instrument in such a manner that the frequency and depth of vibrato increase as the playing tone region becomes higher and in this playing also the harmonic components included in the musical tones becomes less.
Therefore, in the case when an electronic organ is played, if the electronic organ is so designed that substantially the same effects as those added in the playing of the natural musical instrument are added in the playing of the electronic organ, the playing of the electronic organ will have the same effects in tonal quality as those in the playing of the natural musical instrument. Furthermore, with the electronic organ, there is a demand for the addition of the effects opposite to those added in the playing of the natural musical instrument.
SUMMARY OF THE INVENTION
Accordingly, a primary object of this invention is to provide an electronic musical instrument in which two contradictory demands for the addition of tonal effects in the playing thereof are satisfied, that is, not only a demand for adding the same tonal effects as those in the playing of a natural musical instrument but also a demand for adding the opposite tonal effects in the playing are satisfied.
Another object of the invention is to provide an electronic musical instrument in which kinds and qualities of tonal effects can be readily selected and combined as desired by the performer whereby he can express musical effects intended by him in the performance.
The manner in which the foregoing objects and other objects are achieved by this invention will become more apparent from the following detailed description and the appended claims when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram illustrating one example of an electronic musical instrument according to this invention; and
FIG. 2 is a graphical representation indicating the characteristic curves of a variable filter shown in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, there is shown one example of an electronic musical instrument according to this invention in which a vibrato effect, a tremolo effect and a harmonic-component changing effect (hereinafter referred to as "a filter effect") can be attained.
This electronic musical instrument comprises a tone source section 1 including conventional master oscillators, frequency dividers and tone keyers, a vibrato signal generator 2 for producing a vibrato signal V B which controls the master oscillators, a voltage-controlled type variable amplifier 3 for amplitude-modulating tone signal outputs from the tone source section 1 by a tremolo signal V R from a tremolo signal generator 4, and a voltage-controlled type variable filter 6 whose frequency characteristic is changed by a filter controlling signal V F from a filter control signal generator 7.
The tone signal output from the tone source section 1 is frequency-modulated by the vibrato signal V B from the vibrato signal generator 2, so that the vibrato effect having a vibrato speed and depth which are determined by the frequency and amplitude of the vibrato signal V B can be added to the musical tones. The vibrato signal generator 2 is provided with a voltage-controlled type oscillator 2a and a voltage-controlled type amplifier 2b. The oscillator 2a varies its oscillation frequency in accordance with a vibrato-speed controlling voltage signal V BS described later, while the amplifier 2b amplifies the oscillation output from the oscillator 2a at a variable amplification degree determined by a vibrato-depth controlling voltage signal V BD described later. The oscillation output from the oscillator 2a is sinusoidal.
In the variable amplifier 3, the output from the tone source section 1 is amplitude-modulated by the tremolo signal V R from the tremolo signal generator 4 as was described above, whereby the tremolo effect having a tremolo speed and depth which are determined by the frequency and amplitude of the tremolo signal V R is added to the musical tones. The tremolo signal generator 4 comprises a voltage-controlled type oscillator 4a which is controlled by a tremolo-speed controlling voltage signal V RS described later and a voltage-controlled type amplifier 4b which is controlled by a tremolo-depth controlling voltage signal V RD described later.
The oscillator 4a is provided with a switch 5. When the moving contact of the switch 5 is set at a position 5a the oscillator 4a produces a sinusoidal output, while when the moving contact is set at the other position 5b the oscillator 4a produces a saw-tooth output. One embodiment of the oscillator 4a includes a phase-shift oscillator and a relaxation oscillator. The terminal 5a is connected to the power input of the phase-shift oscillator while the terminal 5b is connected to the power input of the relaxation oscillator. The outputs of both oscillators are connected to the amplifier 4b. Other suitable waveshapes such as square wave and triangular wave can be utilized.
The voltage-controlled type variable filter 6 is connected to the output of the variable amplifier 3 for receiving amplitude modified tone signals. The frequency characteristic of this variable filter 6 is changed by the filter controlling signal V F from the filter control signal generator 7 as was described before, for modifying the frequency spectrum of the tone signals passing therethrough. More specifically, in this example of the invention, the variable filter 6 operates in such a manner that it shows higher frequency region suppressing characteristic as is indicated by a curve I in FIG. 2 when the signal V F is small (low dc voltage), while it shows a higher frequency region emphasizing characteristic as is indicated by a curve II in FIG. 2 when the signal V F is great (high dc voltage). A particularly simple embodiment of the filter 6 comprises a first filter section having the characteristic II, shown in FIG. 2, and a highcut tone control circuit (Shunt-type filter) connected in cascade with the first filter section. The filter control signal generator 7 is an amplifier which amplifies a filter controlling voltage signal V FD described later to form the filter controlling signal V F .
The vibrato signal generator 2, the tremolo signal generator 4 and the filter control signal generator 7 are controlled by output voltages from a control panel section 10 which is provided with manipulating tablets on a panel, and in addition by output voltages from an expression-keyboard controlled section 13 which operates in connection with the manipulation of an expression control device 11 and a keyboard 12 as will be described in detail later. These output voltages are the voltage signals V BD , V BS , V RD , V RS and V FD described before.
The control panel section 10 is provided with a vibrato-depth control circuit 21D, a vibrato-speed control circuit 21S, a tremolo-depth control circuit 22D, a tremolo-speed control circuit 22S and a filter control circuit 23D. Each of these control circuits is constituted, for instance, by a potentiometer connected to a dc power source (not shown) to produce a dc control voltage of, for instance, from 0 volt to 10 volts through the manipulation of the respective tablet.
In the expression control device 11, an expression state representing voltage is produced which varies within the range of, for instance, from 0 volt to 10 volts in accordance with the manipulation angle of the foot pedal of the expression control device 11, while in the keyboard 12, a pitch representing voltage is produced which varies within the range of, for instance, from 0 volt to 10 volts in accordance with the tone pitch of the depressed key in the keyboard 12. These two representative voltages are applied to two ends of a mixing variable resistor 26 provided in a mixer 25. Therefore, the expression state representing voltage and the pitch representing voltage thus applied are mixed through the variable resistor 26, the mixing ratio depending on the position of the sliding contact of the variable resistor 26. Thus, the mixer 25 produces an mixed output voltage of from 0 volt to 10 volts.
The mixed output voltage thus produced is applied through change-over switches 41D, 41S, 42D, 42S and 43D to polarity selector circuits 31D, 31S, 32D, 32S and 33D, respectively, which are provided corresponding to the control circuits 21D, 21S, 22D, 22S and 23D on the panel control section 10, for selecting the polarity and value of the mixed output from the mixer 25.
The selector circuit 31D is provided with a variable resistor k. The mixed output voltage described above is applied directly to one of the terminals of the variable resistor k and to the other terminal through an inverter INV. Therefore, when the sliding contact of the variable resistor k is set at one end (+100%) of the resistor k (hereinafter referred to as a "+100% position") the mixed output voltage is applied to the sliding contact as it is; however, when the sliding contact is positioned at the other end (-100%) (hereinafter referred to as a "-100% position"), the mixed output voltage is applied to the sliding contact with its polarity inverted. Thus, an output voltage from the variable resistor k is 0 volt when the sliding contact is positioned at the center of the resistor k (hereinafter referred to as a "0% position"), a voltage of from 0 volt to +10 volts when the sliding contact is positioned on the +100% position side of the resistor k, and a voltage of from 0 volt to -10 volts when the sliding contact is positioned on the -100% position side of the same. The other selector circuits 31S, 32D, 32S and 33D have the same construction as that of the selector circuit 31D. Each of the selector circuits 31D, 31S, 32D, 32S and 33D is provided with a pilot lamp l which is turned on when the output voltage from the variable resistor k is 0 volt. Such a lamp circuit can be arbitrarily designed by an engineer in this field.
The output terminal of the control circuit 21D on the panel control section 10 and the output terminal of the selector circuit 31D in the expression-keyboard controlled section 13 are connected together, if necessary through resistor r 1 and r 2 , respectively. When the switch 41D in the section 13 is off, that is, the movable contact is thrown to the ground side, an output voltage from the control circuit 21D is applied only, as the vibrato-depth controlling voltage signal V BD , to the amplifier 2b in the vibrato signal generator 2. When the switch 41D is on, an output voltage from the selector circuit 31D is also applied, as the vibrato-depth controlling voltage signal V BD , to the amplifier 2b.
The constructions of the selector circuits 31S, 32D, 32S and 33D and the connections between these selector circuits and the control circuits 21S, 22D, 22S and 23D are the same as that of the selector circuit 31D and that between this selector circuit and the control circuit 21D described above. More specifically, when the switch 41S is off (or on), an output voltage from the control circuit 21S (or also the selector circuit 31S) is applied, as the vibrato-speed controlling voltage signal V BS , to the oscillator 2a in the vibrato signal generator 2. When the switch 42D is off (or on), an output voltage from the control circuit 22D (or also the selecting circuit 32D) is applied, as the tremolo-depth controlling voltage signal V RD , to the amplifier 4b in the tremolo signal generator 4. When the switch 42S is off (or on), an output voltage from the control circuit 22S (or also the selector circuit 32S) is applied, as the tremolo-speed controlling voltage signal V RS , to the oscillator 4a. Furthermore, when the switch 43D is off (or on), an output voltage from the control circuit 23D (or also the selector circuit 33D) is applied, as the filter controlling voltage signal V FD , to the amplifier 7.
With the musical instrument thus organized, the addition of tonal effects to musical tones regardless of the expression and pitch of the musical tones can be achieved as on a conventional musical instrument by setting the poles of the switches 41D, 41S, 42D, 42S and 43D at the off-positions. That is the vibrato depth and speed the tremolo depth and speed and the harmonic components included in the musical tone can be changed as much as desired, by manually controlling the control circuits 21D, 21S, 22D, 22S and 23D respectively through the tablets provided on the panel.
In the case where the tonal effects are to be changed relative to the expression and pitch of musical tones, it can be achieved by closing the switches 41D, 41S, 42D, 42S and 43D. In this operation, if the position of the sliding contact of the variable resistor 26 is adjusted, the vibrato depth and speed, the tremolo depth and speed and the harmonic components included in the musical tone can be changed with the variation in sound volume (expression) which is caused by the manipulation of the expression device 11 and the variation in tone pitch which is caused by selectively depressing the keys on the keyboard 12. In this operation, the degrees of contribution of the expression device 11 and the keyboard 12 to the addition of the tonal effects to the musical notes are determined by the position of the sliding contact of the variable resistor 26.
When the switches 41D through 43D are on, the output voltages from the selector circuits 31D through 33D can be 0 volt, a positive voltage, and a negative voltage respectively as the sliding contact of the variable resistor k is set at the 0% position, the +100% position and the -100% position. In this connection, when the sliding contact is set at the 0% position, the tonal effects such as vibrato effect can no longer be changed by the manipulation of the expression device 11 and keyboard 12. When the sliding contact is set at the +100% position, if musical tones are produced with the manipulation of the expression device 11 and the keyboard 12 in such a manner that the sound volume and pitch are increased, the tonal effects such as a vibrato effect increase also. In contrast, when the sliding contact is set at the -100% position, if the musical tones are produced with the manipulation of the expression device 11 and keyboard 12 in such a manner that the sound volume and pitch are increased, the tonal effects decrease.
When the movable contact of the switch 5 provided in the oscillator 4a is set at the position 5a, a tonal effect such as is similar to the tremolo effect on the vibraphone is imparted to the musical tones. When the pole is thrown to the position 5b, a tonal effect such as is similar to the tremolo effect on the mandolin is imparted to the musical tones.
The switches 41D through 43D should be manipulated without causing the production of unnaturalness in the musical tones being played. For this purpose, the circuit shown in FIG. 1 is so formed that the performer should preferably manipulate the switches only when the pilot lamps L are lighted on. Since the output voltages of the selector circuits 31D through 33D are 0 volt when the pilot lamps L are on, the tonal effect control conditions by the control panel section can be smoothly changed to those by the expression-keyboard controlled section 13 without production of unnaturalness in musical tones.
Thus, according to this invention, an electronic organ in which the depth and speed of vibrato, the depth and speed of tremolo and the harmonic components (spectra) included in musical tones can of course be controlled by the control panel section 10 only regardless of the variation in sound volume and pitch of the musical tones, and in addition the tonal effects dependent on the variation in volume and pitch of the musical tones can also be attained in connection with the expression-keyboard controlled section 13. According to the circuit of FIG. 1, the tonal effect control by the expression-keyboard controlled section 13 can be carried out by selectively combining the tonal effect which becomes deeper and faster with the increase of the volume and pitch and also the opposite tonal effect, and therefore the tonal effects intended by the performer can be satisfactorily practiced by the circuit. Furthermore, these effects can be attained by a simple operation such as the manipulation of the switches and the sliding of the sliding contacts of the variable resistors included in the circuit shown in FIG. 1.
This invention has been described in connection with three tonal effects; vibrato effect, tremolo effect and filter effect; however it can be applied to the case also where a sustain effect, marimba effect or the like are to be added to the musical tones.