Abstract: An electronic musical instrument having selectable monaural, stereo and multiple channel musical performance capability is disclosed which includes a performance data generating device; tone signal generating systems; sound producing systems; a mode indicating device; a selection device; and a distribution device. The tone signal generating systems generate musical tone signals based on performance data generated by the performance data generating device. The sound producing systems produce musical sounds based based on the musical tone signals. The selection device allocates performance data to a single musical tone signal generating system when the mode indicated by the mode indicating device is the first mode. The selection device allocates performance data to plural musical tone generating systems when the mode indicated by the mode indicating means is the second mode.

Abstract: A decoder assigns key values according to a system of mathematical weight values in terms of whole and semi-tone intervals of the musical scale, each key contributing its assigned value to the sum when depressed. Any interval along the scale can be reached by any combination of depressed keys that sum to that interval amount from the open "zero reference" position. The result is a woodwind-style keyboard that is perfectly regular and which has no default or unusable fingering combinations.

Abstract: An electronic musical instrument is provided of the type in which a musical tone signal is formed by executing computations according to a mathematical formula such as a frequency modulation formula. Tone formation of each of musical tone signals to be simultaneously formed is assigned to each time-division-multiplexed time channel which is cyclically repeated over cycles of a plurality of time slots. A computation for forming each single musical tone is divided into a plurality of sub-computations, and those sub-computations are executed respectively using a plurality of cycles of time slots of each single time channel. Thus tone formation according to a complex computation formula is realized. Parameters necessary for the computation are generated respectively for each time slot so that any computational formula is adopted as desired by selecting predetermined parameters for each time slot.

Abstract: In a electronic musical instrument wherein a portamento is played by supplying the pitch voltage corresponding to a subsequently depressed key to a capacitor holding the pitch voltage corresponding to a previously depressed key, the charge and discharge currents of the capacitor corresponding to the difference between the two pitch voltages are controlled to vary exponentially thus changing exponentially the capacitor terminal voltage. The terminal voltage of the capacitor is applied to drive a voltage controlled oscillator to vary its oscillation frequency. To vary exponentially the terminal voltage of the capacitor, a mutual conductance converter is connected between the capacitor and a keyboard section and the output current from the mutual conductance converter is controlled by a control signal corresponding to the terminal voltage of the capacitor.

Abstract: A circuit for producing musical tones is disclosed which includes a keyboard for selecting the musical tones, and a tone generator responsive to the keyboard for generating a square wave signal having the frequency of the musical note to be generated. A charging circuit is provided for charging a capacitor to a predetermined level of voltage when the square wave signal is terminated, and for exponentially discharging the capacitor when the square wave signal is initiated. A modulation circuit amplitude modulates the square wave signal in proportion to the capacitor voltage to produce an exponentially decaying signal which simulates the waveform produced by a struck piano string. A speaker is also included to convert the exponentially decaying signal into audible musical tones having the sound of piano notes. The circuit of the invention requires only a small number of components, making it suitable for use in miniature musical toys.

Abstract: An electronic musical instrument in which a single manual keyboard is provided with two voicing blocks which has a certain keyboard space interval therebetween and at least one of which generates a multiple tone corresponding to keys being depressed. There is provided a circuit for providing a certain time interval from a time-divided signal produced by the key depression. This circuit distinguishes between tones from the two voicing blocks, to thereby separate them from each other. There is also a circuit for generating a monophonic or polyphonic tone signal from each of the separated time-divided signals.

Abstract: A preferential circuit for an electronic musical instrument is provided in which a memory circuit is employed to memorize a key data signal corresponding to the last depressed key and at least one key data signal corresponding to the second last depressed key. To drive a tone generator, the memory circuit normally outputs the key data signal of the last depressed key but outputs the signal of the second last depressed key when the last depressed key is released with the second last depressed key being held depressed. If the player depresses an errouneous key and release this last depressed error key, a musical tone corresponding to the second last depressed key is then produced.

Abstract: An electronic musical instrument comprises a power source switch, a keyboard including a plurality of key switches corresponding to a plurality of keys, a signal generator for generating a musical tone signal corresponding to a note of a depressed key, and a loudspeaker driven by an output of the signal generator for producing a musical tone. In the instrument, the power source switch is interlocked with the key depression operation so as to supply power to the electronic musical instrument only when a key is depressed.

Abstract: An electronic musical instrument having combined monophonic and polyphonic sound producing capabilities includes a keyboard simultaneously operating a monophonic tone signal generating circuit and a polyphonic tone signal generating circuit. The tone signals produced by the tone generating circuits are combined and coupled through a single signal processing stage and therefrom to an output speaker. A gate signal for enabling the monophonic tone signal generating circuit and for operating the signal processing stage is derived at the output of a detector circuit which is responsive to the presence of an audio output from the polyphonic tone signal generating circuit.

Abstract: An electronic music synthesizer capable of simulating a wide variety of musical effects, wherein the settings which create the various effects are hard wired on a plurality of selectable circuit boards so that programming of the instrument can be accomplished by the player with minimum effort. The synthesizer encodes a plurality of keys on the keyboard and selects a tone from the tone generator corresponding to the depressed key. This tone is fed through a chain of dividers to create the needed footages, which are then fed to voicing cards that create the different tone sources for the synthesizer. These tone sources are fed into a state variable active filter which modifies the timbre of the tone sources in order to achieve the desired frequency-related effects.

Abstract: A music synthesizer is disclosed which includes a keyboard for entering musical notes to be synthesized into the music synthesizer. The music synthesizer also includes a rhythm control arrangement, such as push buttons, for selecting prestored repetitive rhythm pattern tempos to be synthesized into the music synthesizer. A single microprocessor computer is provided which processes and establishes priority of signals from the keyboard and the rhythm control buttons for generating signals indicative of the frequency and amplitude of the musical note to be synthesized and for generating musical instrument signals and combining them into the rhythm pattern to be synthesized. A tone generator is provided which is controlled by the computer for generating a squarewave signal having the frequency of the musical note to be synthesized.

Abstract: An electronic musical instrument of a key code processing type includes a single tone generating section for producing a solo performance effect without providing a solo performance keyboard. This single tone generating section comprises a single data selection circuit which selects the highest (or lowest) note from among notes of depressed keys for producing a single musical tone. The single data selection circuit includes first and second memories and a comparison circuit. An input key code A is compared with a key code X stored in the second memory and the input key code A is stored in the first memory if the value of the input key code A is greater than the value of the key code X. When one cycle of the above described comparison has been completed, the data stored in the second memory is rewritten with the data of the first memory. The key code for the highest note is now stored in the second memory to designate a tone signal to be produced for a solo performance.

Abstract: A brass keyer system for an electronic organ wherein the keyboard is multiplexed to produce a polyphonic serial data stream, which is then converted to a monophonic serial data stream containing a keydown signal in a time slot corresponding to the highest note played on the keyboard. The monophonic data stream is converted to a multiple bit binary word that is used by the tone generation and keying portion of the system to produce a rectangular wave tone corresponding in frequency to the highest depressed key and having amplitude and pulse width modulation on attack and decay so as to produce a brass tone. The monophonic serial data stream is demultiplexed by means of a recirculating delay loop which repetitively recirculates the keydown pulse for the depressed key. The number of recirculations of this pulse are counted by a first counter and the position of the pulse within the delay loop is registered by a second counter, which is synchronized with the multiplexer.

Abstract: An electronic musical instrument includes a tone signal generator whose operation is controlled by active electronic signal processing. The instrument includes both tone effect control means to provide an alternating current control signal to the tone signal generator and manually operable tone frequency control means having selectively variable resistance and selectively variable capacitance characteristics, with one of these characteristics being variable among logarithmically spaced increments and the other characteristic being variable among linearly spaced increments.

Abstract: In a tone generating apparatus for an electrical music instrument having an array of switches corresponding to respective keys of a keyboard and which are selectively actuable by manipulation of the respective keys, a timing signal generator, preferably including a shift register, has a repetitive operating cycle and is connected with the switches for providing timing signals in response to actuation of the latter, with each of the timing signals occurring at a time during the operating cycle which corresponds to the position of the respective actuated switch in the switch array, an exponential signal generator provides an exponential signal in synchronism with the operating cycle of the timing signal generator, a sample and hold circuit receives the exponential signal and is operative to sample and hold a value of the exponential signal in dependence on the time of occurrence of a timing signal in the operating cycle, and variable frequency oscillator controlled in accordance with the value of the exponentia

Abstract: An electronic musical instrument includes a linear voltage divider network including a plurality of equal series resistance elements for generating a first output voltage as a function of the state of a plurality of tone select keys. This first voltage is converted to a second voltage which selectively varies exponentially as a function of the selected tone. The second voltage is compared with a ramp generator output to set and reset a latch which generates an audio frequency signal thereby. The audio frequency signal is coupled to an octave generator controlled by octave select keys for outputting the tone in a selected octave for output as sound via a speaker. Sharp and flat keys are also provided to cause the first voltage to vary in a way which emulates the functioning of a standard keyboard.

Abstract: In an electronic musical instrument with two tone generators of which the frequency of the tones produced by them is substantially constant for the first generator a priori and for the second generator not until after a final value is reached which corresponds to the frequency of the corresponding tone of the first generator, the frequency of the first generator is applied to a first input and that of the second generator to a second input of a frequency comparator circuit, whose output is connected to a control input of the second generator via control device. This ensures that the repeated readjustments of the control quantities necessary in known instruments are no longer necessary.

Abstract: An electronic musical instrument includes a pitch determining voltage signal generating circuit adapted to produce one of 12 pitch determining voltage signals having different magnitudes corresponding to 12 notes in one octave in response to any of keys belonging to different octave ranges in a keyboard and having the same note name. A pitch determining voltage signal common to the different octave ranges is converted by a voltage converting circuit and taken out as a voltage signal having a magnitude corresponding to the note of a key being depressed on the keyboard. The voltage converting circuit includes a voltage dividing network having a plurality of output points and gate circuits connected to the output points, respectively. Each gate circuit is enabled in response to the depression of a key belonging to a corresponding octave range.

Abstract: A sample hold arrangement for a key signal in an electronic musical instrument in which a keyboard circuit generates a voltage corresponding to a depressed key. The keyboard circuit is connected at its output terminal to an input terminal of a comparator. An output terminal of the comparator is connected to a memory capacitor and a buffer circuit through two gates connected in a series with one another. An output terminal of the buffer circuit is connected, in turn, to a second input terminal of the comparator, and one of the two gates is connected with its control electrode to a detection circuit. A circuit closing signal is generated by the detection circuit when the potentials of the two input terminals of the comparator become substantially equal. The other one of the two gates is connected with its control electrode to an output terminal of a keying signal generator which generates a keying signal of the keyboard circuit.

Abstract: A circuit in an electronic keyboard musical instrument for preferentially selecting the highest and lowest tones from among the tones in chords produced by keys on the keyboard which have been struck. The circuit has a set of series connected resistors having equal values, the number of resistors in the set corresponding to the number of tones from which the highest and lowest tones are to be selected. An end resistor is connected between each end of the set of resistors and a reference voltage level. A plurality of transistors corresponding to the number of resistors each has the emitter thereof connected to the set of resistors between the corresponding resistor and the resistor corresponding to the next adjacent transistor, and has the collector thereof adapted to receive a corresponding tone signal. A keyswitch is connected to the base of each transistor and to a bias source.

Abstract: A monophonic system includes means for voicing only tones derived in response to depression of a key associated with the highest pitched note when several keys are struck at approximately the same time, regardless of the order in which the keys are struck. If several keys are released at approximately the same time, only the tones derived in response to the highest remaining activated key are voiced, regardless of the release sequence. In response to the system being played legatissimo, voiced tones gradually shift in frequency, i.e., portamento is achieved. In response to the system being played staccatissimo, voiced tones shift in frequency in discrete steps.

Abstract: A shoe provided with a plurality of keys on the underside thereof which when depressed will produce various musical tones by means of an electronic circuit provided inside the shoe.

Abstract: A monophonic electronic music synthesizer in which keying signals are collected on common note busses and common octave busses. Tone signals from a top octave tone generator are gated by separate note gates controlled by keying signals on common note busses to select the note tone signal regardless of octave. A chain of frequency dividers fed by the note tone signal produce octavely related tone signals which are gated by separate octave gates controlled by keying signals on common octave busses. A preferred embodiment especially useful in an integrated organ-synthesizer system employs a low octave lockout circuit to select an active highest octave of actuated keyswitches and a preference gating arrangement for tone signals to produce high note select gating of monophonic tone signals. A D.C. keyed volts per octave circuit is also disclosed.

Abstract: This invention discloses control circuitry for an electronic musical instrument including a keyboard, a voltage divider circuit coupled to the keyboard to provide a pitch determining voltage signal corresponding to a depressed key, a storage capacitor for storing the pitch determining voltage signal, voltage-controlled tone signal generating means responsive to the pitch determining voltage signal and adapted to produce a tone signal corresponding to the depressed key, and control voltage waveform generating means responsive to a trigger signal and adapted to produce a control voltage waveform which is coupled to the voltage-controlled tone signal generating means so as to control the tone signal to be generated thereby.

Abstract: An electronic musical instrument includes an oscillator for generating a signal at a frequency corresponding to that associated with a depressed key of the keyboard. The key selects a control voltage, from an exponential voltage divider, for controlling the frequency of a voltage controlled oscillator, which produces a frequency which is directly proportional to the control voltage and inversely proportional to a reference voltage. The reference voltage compensates for variations in the level of the supply voltage, so that the oscillator frequency is independent of the supply voltage.

Abstract: An electronic musical instrument comprising a voltage controlled oscillator, a voltage controlled filter, a voltage controlled amplifier and envelope generators. An output envelope of the envelope generator has various parameters such as rise time and decay time or times. The envelope generator is of the voltage controlled type so that the parameters of the output envelope of the envelope generator are controllable in response to parameter controlling voltages from a parameter controlling voltage generator. In an attempt to enhance performance effects a switch circuit is provided, in accordance with the invention, to interchange between a rise time controlling voltage and a decay time controlling voltage which are both coupled from the parameter controlling voltage generator to the envelope generator.

Abstract: This invention relates to a voltage controlled type electronic musical instrument comprising a keyboard section for generating a pitch determining voltage signal and a trigger signal upon key operation, a voltage controlled tone signal generating circuit including a voltage controlled oscillator, voltage controlled filter and voltage controlled amplifier for generating a tone signal in response to the pitch determining voltage signal and control wave generating circuits responsive to the trigger signal for generating control waves coupled to the voltage controlled oscillator, voltage controlled filter and voltage controlled amplifier. The pitch determining voltage signal is coupled to the voltage controlled amplifier so as to control the gain thereof, thereby decreasing the volume of musical sounds at higher frequency from that of musical sounds at lower frequency.

Abstract: This invention is directed to a keyboard circuit for generating pitch determining voltage signals whose voltage values exponentially vary with respect to notes. Key switches are connected between a DC voltage source and a voltage dividing resistance network, thus making it possible to use key switches having a simpler contact construction. Nevertheless, the keyboard circuit of the invention can act as a lower or higher tone preference circuit.

Abstract: An electronic musical synthesizer generates tone signals coupled to a controllable bandpass filter and a controllable low-pass filter. A plurality of voice switches are individually selectable to couple preset control voltages to the filters, and to enable potentiometers which can be adjusted to generate control voltages to vary the frequency characteristics of the filters, control the octave of the tone signals, and to control a modulation oscillator. When a variable/preset switch is set to a preset state, the potentiometers are disconnected and auxiliary sections of the selected voice switch presets voltages for the oscillator, the octave circuit and the filters.

Abstract: In a electronic musical instrument wherein a portamento is played by supplying the pitch voltage corresponding to a subsequently depressed key to a capacitor holding the pitch voltage corresponding to a previously depressed key, the charge and discharge currents of the capacitor corresponding to the difference between the two pitch voltages are controlled to vary exponentially thus changing exponentially the capacitor terminal voltage. The terminal voltage of the capacitor is applied to drive a voltage controlled oscillator to vary its oscillation frequency. To vary exponentially the terminal voltage of the capacitor, a mutual conductance converter is connected between the capacitor and a keyboard section and the output current from the mutual conductance converter is controlled by a control signal corresponding to the terminal voltage of the capacitor.