Abstract: A circuit for producing a chorus effect in an electronic musical instrument. The circuit includes N separate channels, where N is an integer greater than one, with each channel having an analog delay line to which a tone signal is applied. Each delay line frequency modulates the applied tone signal at a subaudio rate in response to changes in the frequency of clock pulses applied to the delay lines. The delay variations in one delay line are out of phase with the delay variation in every other delay line by a selected amount which is normally 360.degree./N. Clock pulses are generated by means including a nonlinear circuit to compensate for the nonlinearity in the frequency interval between tones in the musical scale. The outputs from the delay lines after filtering of the clock frequency components are utilized to produce the desired chorus effect output from the instrument.

Abstract: Touch responsive control of note amplitude and harmonic content is achieved by providing each key with a touch responsive transducer. A set of attack/decay scale factors are accessed sequentially from a memory and used to establish the amplitude envelope of the generated note. The accessed scale factors are modified by the transducer output to effectuate touch responsive amplitude control. In a preferred embodiment, scale factors stored in consecutive memory locations define a piano-like attack/decay envelope. The transducer output sets the initial memory access location, so that the harder the key is struck, the greater the initial amplitude of the generated note.Other embodiments include touch responsive control of the constituent Fourier components of the generated tone; and utilization of multiplexing for time shared connection of plural analog touch responsive transducers to a single analog to digital converter.

Abstract: Modulation systems for electrical signals representing music in which synchronous vibrato and tremolo modulations are applied to a flute signal in one channel, the vibrator being produced by a bucket brigade modulator and the tremolo by a balanced modulator in cascade with the bucket brigade modulator, and in which in a second channel tones other than flute tones, and pedal tones, are separately treated to have independent vibratos, and in which balanced modulators for modifying the amplitude of the tone signals are concurrently controlled by a common expression voltage. In one modification flute signals are vibrato modulated in opposed phases, and passed via diverse filters to a common tremolo modulator. Provision is made for combining the inputs of the channels, the outputs of which are electroacoustically transduced by separated loudspeakers. Provision is made for slowly varying the frequency of a sub-sonic modulating oscillator, which is either turned off, or operates at about 1 or about 6 Hz.

Abstract: An electric organ utilizes digital encoding and time division multiplexing to both transfer function selection and note selection information from manually operable switches to respective memories, and to simultaneously produce a plurality of tone signals corresponding to stored note selection information. A single encoding circuit during successive scanning periods established by a single multiplexing circuit encodes in binary form the function and note selection information. A plurality of stored note codes are transferred on a time division multiplexing basis to a note selector which selectively produces in multiplexed form on one output all of the tone signals. These tone signals are demultiplexed to generate a corresponding plurality of tone signal outputs. An octave selection circuit responsive to a part of each note code selectively reduces the frequency of the demultiplexed tone signals.

Abstract: An electrically amplified musical instrument control apparatus for combining control of a broad range of special sound effects in a single housing and enabling a musician to produce single or multiple special sound effects as desired with a guitar while indicating the operational status of each special effect and providing a foot-operated volume control.

Abstract: A musical-tone signal forming apparatus for an electronic musical instrument is characterized by the use of a musical-tone waveform setting circuit by which repeatedly at least one cycle of a musical-tone waveform is sampled at n points so the amplitude thereof at each sampling point can be compared with the amplitude thereof at the preceding sampling point and an increase signal, an equal signal, or a decrease signal is generated as a digital signal. Also employed is an envelope setting circuit in which an envelope of a musical tone is sampled at m points and the analog amount thereof at each sampling point is generated as a corresponding digital signal. An integrating circuit is used in which the digital signals of the envelope setting circuit are accumulatively added or subtracted according to the digital signals of the musical-tone waveform setting circuit. The output signal of the integrating circuit is taken out through a D-A converter as a musical-tone signal.

Abstract: An electronic musical instrument has a ring oscillator incorporating a multiplicity of identical stages connected to form a ring with the output of each stage being connected to the input of the succeeding stage. Each stage has an RC time constant circuit which introduces a delay in the transmission of a signal from one stage to the next, in accordance with the value of the capacitance of the RC circuit. The capacitance is varied in response to the amount of pressure acting on a key of the keyboard of the musical instrument, and the interval between a succession of pulses presented to an output terminal of the oscillator is dependent upon the force with which the keys are depressed, and the positions within the output pulse train at which such delays are introduced is dependent upon the position of the keys of the keyboard. The output pulse train contains information identifying all of the operated keys of the keyboard and the force with which they are operated.

Abstract: The electronic musical instrument according to the invention produces excellent tone color effect by changing filter characteristics discontinuously from the start of generation of a musical tone.A plurality of filter characteristics each represented by a deflecting line consisting of straight lines (these filter characteristics being different from each other in coordinates at each point of deflection as well as inclination of each straight line) are stored in memory. These filter characteristics are sequentially read out with the lapse of time and level information of each harmonic constituting a musical tone is obtained by calculating a primary functional formula of the straight line region in which the read out filter characteristic belongs. The level of each harmonic is controlled in response to this level information.

Abstract: The stop control for an organ console comprises a panel including groups of touch sensitive switches disposed in pairs with an adjacent indicating lamp, wherein the switches of a pair respectively actuate and deactuate a given stop while the lamp indicates whether the stop is actuated. The switches of a pair are connected to set and reset terminals of a latching circuit which provides an output for energizing the indicating lamp and for controlling appropriate stop circuitry in the organ. The touch sensitive switches are disposed in groups according to the organ manual or function to which the corresponding stops pertain. A general cancel switch returns the various latching circuits to a reset condition. A transposer control circuit includes a plurality of switches and adjacent indicating lamps wherein the depression of a particular switch operates a latching circuit and resets other latching circuits associated with the transposer.

Abstract: Apparatus is provided for use in electronically creating music or special sound effects through the generation and modification of audio frequency, electrical, tone sequence signals. The apparatus is characterized by its ability to generate random, as well as cyclically patterned, tone sequences; by the degree of control provided over both basic parameters of generation and a number of available special modifying effects; and by the reliability of the apparatus and the relative economy with which it may be maufactured. The preferred form of apparatus employs functional stages or modules largely implemented with solid state components. Among the novel functional modules utilized in the apparatus is an improved type of low pass, electronic R-C ladder filter employing diodes and fixed value capacitances, rather than transistors or/and variable value capacitances.

Abstract: An automatic rhythm performing apparatus comprises a rhythm pattern generator for generating stressed beat pattern pulses representative of stressed beats of a rhythm to be generated and relaxed beat pattern pulses representative of relaxed beats of the rhythm, a tone generator, a rhythm gate coupled to the tone generator and a mute gate coupled to the rhythm gate. The rhythm gate is operative to impart a decayed envelope to a tone signal from the tone generator in reponse to each of the stressed beat pattern pulses and the mute gate is operative to suppress a portion of a decayed output signal from the rhythm gate in response to each of the relaxed beat pattern pulses. The automatic rhythm performing apparatus can be used for an automatic chord performance of a keyboard type electronic musical instrument.

Abstract: An automatic rhythm producing apparatus is capable of emphasizing a rhythm pattern of a desired percussion instrument among a plurality of rhythm patterns which constitute a rhythm. The rhythm producing apparatus has a pulse level control circuit for controlling the pulse level of a selected rhythm pattern signal among a plurality of rhythm pattern signals. This circuit is provided between a rhythm pattern forming circuit and a rhythm selection circuit. The apparatus also comprises control means for controlling the output of the rhythm selection circuit to prevent variation in the average level of the entire rhythm sound. Another example of the inventive apparatus further discloses means for controlling power voltage in a frequency dividing circuit.

Abstract: A percussion processor for an electronic musical instrument, such as an electronic organ in which information representative of the actuation of selected switches corresponding to associated notes of the musical scale is furnished in the form of a time-division multiplexed signal having repetitive sequences of time slots, includes a delay circuit comprising a shift register having a time delay period equal to the duration of one of the sequences of time slots or an integer multiple thereof. The multiplexed signal train is applied to the delay circuit and also is applied in parallel to an inverter circuit. The output of the inverter and the output of the shift register are connected to different inputs of a NAND gate.

Abstract: A transposition apparatus for an electronic musical instrument such as an electronic organ is disclosed. The transposition apparatus permits the playing of a musical score in any desired key regardless of the key actually being played. The apparatus converts the actual keying pattern to a serial bit pattern which is then delayed by a desired number of bit positions. The delayed serial bit pattern is then converted back to a keying pattern to actuate the tone generator of the instrument.

Abstract: A rhythm unit produces repetitive pulses having one of a plurality of selectable predetermined time relations to each other for use as rhythm or accompaniment signals in an electronic organ or the like. Each of the pulses triggers operation of a modulator for modulating accompaniment tones in time with pulses produced by the rhythm unit, in correspondence with a programmed pattern. The shape of the modulated envelope waveform, its amplitude, and its frequency composition are programmed in accordance with a prearranged sequence, to give the desired sound characteristic within each of a plurality of individually selectable rhythms.

Abstract: A device for modulating a musical tone signal to produce a rotating sound effect. A first channel is coupled to an input for a musical tone and has an amplitude modulator therein. At least two further channels each having an amplitude modular therein are coupled to the input through a delay circuit. A frequency modulator is coupled to the amplitude modulator in the first channel and to the delay circuit means for frequency modulating the musical tone signals therein and phase shifters are coupled between the frequency modulator and the respective amplitude modulators in the further channels for shifting the phase of the musical tone signal in the channels.

Abstract: Apparatus for converting the relatively rapid rise time, relatively long fall time tone envelopes of a music source output to envelopes having relatively long rise time and relatively rapid fall time includes a sawtooth relaxation oscillator whose output feeds a modulator which is also fed by the music source. The oscillator is turned on via a transistor switch when the average power of the signal at the output of the modulator exceeds a predetermined reference threshold signal.

Abstract: A waveform converter for an electronic musical instrument wherein an input rectangular wave tone signal is supplied to a frequency-voltage converter to generate a D.C. voltage control signal having a voltage level corresponding to the frequency of the input rectangular wave tone signal; and a one-shot multivibrator is triggered by the input rectangular wave tone signal to produce an output rectangular wave tone signal having the same frequency as the input rectangular wave tone signal. The one-shot multivibrator comprises duty factor control means responsive to the D.C. control voltage signal for determining the duty factor of the output rectangular wave tone signal.

Abstract: An electronic musical instrument comprising first and second musical tone signal synthesizing circuit arrangements including voltage waveform generators adapted to control first and second tone signals to be generated by the first and second musical tone signal synthesizing circuit arrangements. First and second memory groups including a plurality of waveform parameter controlling information memories are provided for control of the voltage waveform generators in the first and second musical tone signal synthesizing circuit arrangements. A memory selector includes the same number of preset switches as that of the memories in each of the first and second memory groups.

Abstract: An electronic musical instrument capable of producing a multi-system tone source effect which is an effect providing a musical tone with naturalness and resulting from simultaneous playing of a tone of a proper pitch and a tone of a pitch slightly different from the proper pitch. The inventive electronic musical instrument produces this effect with a smaller number of tone source devices than the number of systems.Composite musical tone waveshape amplitudes achieving the multi-system tone source effect can be represented by a single multiplication term of a sine waveshape function content corresponding to a certain pitch and a cosine waveshape function content corresponding to a pitch difference. According to the invention, the sine waveshape function content and the cosine waveshape function content are separately produced and these contents are multiplied with each other to produce the composite musical tone waveshape amplitudes.

Abstract: An arpeggio circuit for an electronic keyboard instrument has means for generating a desired sweep voltage which is continuously varied, a voltage control type oscillator connected to the generator for generating a sweep frequency which is varying in proportion to the sweep voltage, a plurality of pulse generating means, one for each note of the keyboard instrument, and each having a series connected resonance circuit means and pulse forming means for forming a pulse in response to the output from said resonance circuit means. The pulse generating means are connected to the oscillator in parallel with each other.

Abstract: An electronic music synthesizer including a keyboard control system for enabling multiple independent voice channels (voices) to be controlled by the keyboard in a musically pleasing manner. The control system responds to a keyboard of M keys to control N voices where N<M; e.g. M=64 and N=10. The voice channels are preferably identical to one another, each being comprised of voltage controlled elements such as an oscillator (VCO), amplifier (VCA) and filter (VCF). Typically, the control system selects an available voice channel and in response to a key depression, supplies a DC control voltage thereto whose level is nominally linearly related to the note corresponding to the depressed key. In addition to the control voltage, the control system supplies a gate signal to the selected voice channel indicating the time duration of the key depression.

Abstract: An automatic rhythm accompaniment apparatus for an electronic musical instrument is characterized in that the same comprises a plurality of chord-memory circuits which detect and memorize respective first tones in respective bars of a melody played by the operation of keys, and a chord gate circuit which is driven by output signals of these chord memory circuits and rhythm pulses generated by a rhythm pulse generator so that, by opening and closing of the chord gate circuit, there is obtained rhythm-accompaniment tones caused by the first tones in the respective bars. A key selection circuit is provided at the front stage of the chord gate circuit so that rhythm accompaniment tones according to a key of the melody played may be obtained. A chord change-over circuit can be provided preceding the chord gate circuit so that a key of the melody can be selected. Rhythm-accompaniment tones of different chords appearing in the middle of the melody may be obtained.

Abstract: An apparatus for forming a musical-tone waveform for an electronic musical instrument characterized in that at least one cycle of a musical-tone waveform, which it is desired be produced, is divided in amplitude by dividing lines at equal intervals and sampling points on a time axis are determined from respective crossing points between the waveform and the dividing lines and the distance between the initial and the final sampling points is represented by an appropriate number of pulses so that each sampling point may be represented by a pulse number. There is further provided a memory circuit wherein each sampling point, that is, the pulse number thereof is set up in the form of a digital signal. Additionally, there is a set up in the form of a digital signal a tendency such as increase, decrease or equal at each sampling point with reference to the preceding sampling point.

Abstract: A separate group of function preset controls is provided for each of a plurality of individually adjustable functions, to select predetermined values for such functions or, alternatively, to allow manual adjustment thereof. A supervisory preset control is provided for controlling the operation of several different function preset controls, in accordance with an overall plan including predetermined settings for a plurality of functions. In one mode of operation of the supervisory preset control, each of the function preset controls is placed in its manually adjustable mode, so that the individual functions are all controlled by manual adjustment. In other modes of operation, each of the function preset controls is placed in one of its fixed modes, to establish a predetermined fixed combination of function settings.

Abstract: A keyboard arrangement in electronic musical instrument comprising playing keys movable to cover a predetermined distance in normal play and also being able to move farther in excess of said distance in accordance with the pressure applied to the keys, a movable arm arranged at position corresponding to each key at its depressed position, and a sensor means provided for said arm to detect the amount of the excessive distance covered by the movable arm and the speed thereof to generate a signal to be used for the control of expression such as tone volume, tone color and the like.The keyboard arrangement preferably further includes a deformable cushion means normally nondeformingly contacting, at its upper end, the bottom surface of the movable arm member during the normal movement of the positionally corresponding key but is deformed when the key makes a movement in excess of the normal distance to be covered by the key.

Abstract: To provide a chorus effect in a digital musical instrument frequency separation between tones read out of two or more memories is effected by modifying the coded digital number which controls the rate of change of voice addresses in a memory by a predetermined value to produce a modified coded digital number, and then using said coded digital number and the modified coded digital number to read voices out of two or more memories.

Abstract: This invention provides an electronic musical instrument comprising a keyboard circuit for producing a pitch determining voltage signal representing the note of an operated key, a voltage controlled oscillator for producing a tone signal having a tone pitch determined by the pitch determining voltage signal, and a voltage controlled lowpass filter for imparting a desired tone color to the tone signal. The voltage controlled lowpass filter is responsive to the pitch determining voltage signal from the keyboard circuit to control the cutoff frequency of the voltage controlled lowpass filter in such a manner that the harmonic content of a higher tone signal is decreased from that of a lower tone signal.

Abstract: A selective distortion control circuit for an electrical musical instrument employs a cathode or emitter follower valve having a load resistance that is selectively changed to provide either a clean or distorted output signal. The mutually in-phase clean input and distorted output of the valve are connected to opposite sides of a potentiometer of which the wiper provides a selectively proportioned mixture of clean and distorted signals. The relative amount of distortion may be selected, and once selected, the operator may readily choose between clean and distorted sound by changing the load resistance.

Abstract: In a computor organ, musical tones are generated by separately evaluating the constituent Fourier components of a musical waveshape and summing these to obtain the waveshape sample point amplitudes. The relative amplitude contribution of each Fourier component is established by a harmonic coefficient. In accordance with the present invention, pulse-type tone generation is simulated by using harmonic coefficient values associated with the frequency spectrum of a pulse train of particular pulse shape. For example, the coefficients may be given by the Fourier transform associated with repetitive pulses.To simulate pulse width modulation effects, a set of such coefficients is stored in a memory, the set having more coefficients than the maximum number of Fourier components included in each amplitude computation. Pulse trains of different pulse width are simulated by utilizing different subsets of the stored coefficients in the amplitude computation.

Abstract: An electronic musical instrument capable of transposition has a high frequency oscillator provided on its output side with an octave frequency divider comprising twelve counter circuits to generate twelve tone signals based on a twelve tone tempered scale. These tone signals are respectively frequency-divided by respective pluralities of counter circuits to obtain a plurality of octave tone signals. An oscillator for transposition comprising a plurality of counter circuits is provided and the output terminals of these counter circuits are selectively connected to an input terminal of the octave frequency divider such that the oscillation frequency generated from the high frequency oscillator is added to the oscillation frequency generated from the transposition oscillation to produce an input frequency for the octave frequency divider. A frequency divider is provided at the output of the oscillator.

Abstract: A plural mode envelope generator in which a basic time constant circuit is coupled by selector switches to a plurality of envelope generating means which function under the control of one or both of a keydown detector and a legato pulse generator. Fast attack-short substain and slow attack-long sustain envelope circuits involve standard techniques. A dual mode percussion circuit provides post key release sustain in one mode when the keydown detector is decoupled from the circuit and post key release tone snubbing when the keydown detector is coupled to the circuit. A sostenuto circuit with flip-flop latch includes a reset gate to hold the flip-flop in reset until sostenuto keying is desired whereupon a unidirectional circuit couples the initial keydown signal to the latch to place the flip-flop in a set state but prevents the disappearance of that signal from resetting the latch.

Abstract: A new, performer played, real time, multitional, multimbral musical instrument consists of speed and force sensitive keys in which time domain multiplexing is used to find and associate one and only one tone generator, not otherwise busy, with any key that is depressed. The sound generator disclosed can provide very realistic simulations of the flute, oboe, trumpet, French horn, trombone through the provision of various types of modulations in amplitude and frequency of the various partials, as is characteristic of each instrument simulated, and filtered noise. Glissandi are provided from one note to another and are controlled from the pair of keys involved by the relative pressure with which they are depressed. For the nonpercussive tonalities, the speed with which a key is depressed, which is determined by differentiating the force, may be used to cause the attack transient to behave in a manner very characteristic of the instrument being simulated.

Abstract: A new, performer played, real time, multitonal, multimbral musical instrument consists of speed and force sensitive keys in which time domain multiplexing is used to find and associate one and only one tone generator, not otherwise busy, with any key that is depressed. The sound generator disclosed can provide very realistic simulations of the flute, oboe, trumpet, French horn, trombone through the provision of various types of modulations in amplitude and frequency of the various partials, as is characteristic of each instrument simulated, and filtered noise. Glissandi are provided from one note to another and are controlled from the pair of keys involved by the relative pressure with which they are depressed. For the nonpercussive tonalities, the speed with which a key is depressed, which is determined by differentiating the force, may be used to cause the attack transient to behave in a manner very characteristic of the instrument being simulated.

Abstract: The keyboard type instrument includes circuitry for controlling an envelope generator and a voltage controlled oscillator which in sequence operates a voltage controlled filter, and a voltage controlled amplifier both of which receive control signals from the envelope generator. The keys of the keyboard preferably have a common variable conductance touch sensor or transducer associated therewith which is responsive to key depression pressure in excess of a predetermined threshold pressure to control one or more audible characteristics of the played note. In one embodiment vibrato, pitchbend, brilliance and volume of the note are controllable. Associated with the keyboard is selection means including a plurality of audible characteristic selectors and variable means delimiting the range of the audible characteristics.

Abstract: A method of and apparatus for increasing the fullness of tone of electronic musical instruments having at least one set of tone generators corresponding to the tonal range of the instrument through the playing of individual registers and/or groups of registers optionally selectible from these tone generators, by one or more key systems. Electric sound oscillations which are provided by the tone generators and optionally combined to form registers are subjected to cyclic phase shifts, the period of the cycle of which is so low that these shifts are not acoustically discernible in the individual sound or register or group of registers.

Abstract: For use in an electronic musical instrument, such as an electronic organ, a first set of tone generators, preferably of the type where all of the notes of a musical scale are obtained by frequency division from a single frequency stable master oscillator, operates together with a second set of tone generators comprised of a plurality of individually tunable chorus oscillators for generating the notes of a musical scale in a frequency range where the sensitivity of the human ear to ensemble or chorus effect is appreciable. The chorus oscillators are individually adjusted to beat with and produce chorus effects with corresponding notes derived from the first set. In addition, the entire set of chorus oscillators is capable of being simultaneously and proportionally raised or lowered in pitch by applying a control voltage to a frequency control terminal.

Abstract: Timing signals of adjustable rate are estabilished digitally in an electronic musical instrument through the use of digital timing numbers. A selected one of such numbers is repetitively added to the contents of an accumulating adder at a fixed rate. A train of timing pulses is obtained from one bit output of the adder; the rate of these pulses is directly related to the value of the selected timing number. Alternatively, consecutively updated parallel bit timing codes can be obtained from plural bit outputs of the accumulating adder. These timing codes, which are incremented or decremented in value by amounts established by the selected timing number, are useful for directly addressing a memory containing a set of musical instrument factors that are to be utilized on a time dependent basis.

Abstract: The invention relates to an apparatus for producing a vibrato effect in acoustic signals, particularly for electronic organs, in which the output signals are obtained by successively scanning a plurality of points of a delay line fed by the acoustic signals.

Abstract: An electronic organ includes digital circuitry for automatically enabling in a sequential manner a plurality of gates to pass tone control signals to keyers which generate corresponding tone output signals. The digital circuitry includes a tone counter which sequentially enables a plurality of tone gates, and an octave counter which sequentially enables output gates having inputs from the tone gates. A clock generates clock pulses which are rapidly counted by the note counter to sequentially scan the note gates. When a tone control signal is passed, the output of a note detector causes a divider to be inserted between the clock and the note counter to maintain enabling of the note counter.

Abstract: A low power consumption, compact portable stereo radio transmitter and a receiver therefor, the transmitter having two audio processing channels each for receiving inputs from two stereo pickup stations and including amplifier circuits with selector switches providing a mode of even harmonic generation, a mode of odd harmonic generation, and a mode of undistorted amplification, a 38 KHz oscillator, flip flop coupled to the oscillator to provide a 19 KHz pilot signal, a difference amplifier and a balanced mixer to produce a double-sideband suppressed carrier signal centered on 38 KHz, and an amplifier for combining the balanced mixer output, the pilot signal and the two channel output and modulating a carrier signal. The receiver includes amplifier, detector, and decoder circuitry to receive the radio signals from the transmitter and produce stereo audio signals for driving a standard stereo amplifier.

Abstract: An electrical organ in which each of the keys of the organ is mechanically coupled to one single pole single throw electrical switch, and a plurality of said switches are each connected to a plurality of photoelectric tone sources through pulse shaping keying circuits, the keying circuits connected to each key switch being connected in a cascade circuit with the direct current potential source and the photocell of one of the tone sources, the other tone sources having photocells connected to the junctions of keying circuits in said cascade circuit. The tone circuits actuated by a given key of the organ may be at the same frequency or may comprise a chiff tone component or a noise-puff component, or may include a special decay circuit which activates a photocell modulated at a different pitch from the main-tone component.