Abstract: There is disclosed herein a music synthesizer which responds to a music note played by a music instrument. The synthesizer has an envelope generator which generates a control signal in relation to the input signal to control the loudness of the synthesized note. Also, the synthesizer has a pair of voltage controlled oscillators, one of which provides a signal having a frequency related to the frequency of the input note, and the other of which provides a signal having a frequency related to the frequency of the input signal offset by the ratio of the difference between a programmed note and a referenced note, such as A440. The programmed note is that note following the operation of a control switch. The synthesizer further includes a series of footpads which control various functions of the synthesizer, such as programming the programmed note, to allow the user to control the synthesized sound while playing an instrument.

Abstract: A digital technique for triangular musical waveform generation is disclosed. A musical scale value corresponding to a selected note is repetitively added to produce an ascending series of non-consecutive numbers which is stored in a latch. A carry output from the limited modulus latch is used to switch a flip-flop which then enables an inverter to reverse the slope of the number series. Alternating reversals produce a rising and falling numerical staircase of controllable slope. This can be directly converted into a smooth triangular waveform, or alternatively it can be used as a series of memory addresses for table look-up purposes. The triangular waveform may be symmetrical, or it may have a controlled degree of asymmetry. Duplicate triangular waveforms with a small frequency mismatch may be used to produce a chorus effect. Or plural triangular waveforms with octavely related frequencies may be used as footages related to a single note, again with a slight frequency mismatch for chorus purposes.

Abstract: The guitar has a novel feedback arrangement for sustaining the sound generated from the strings and including a pickup associated with each string and a corresponding driver intercoupled with the pickup in a feedback loop that also includes a gain-controlled amplifier. The amplifiers are controlled in common from a variable control means. The pickups, drivers and associated electronics are all commonly mounted from the bridge. In an alternate embodiment of the invention there is provided an improved sustain technique that provides a more natural sustain characteristic, employing a parametric type of excitation. This embodiment may comprise a pickup, amplifier and tensioning member responsive to the output of the amplifier for sustaining string vibration by causing longitudinal string displacement by means of the tensioning member. In a similar embodiment the string tension may be held constant and the string length varied instead.

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 tri-state encoding circuit for use with an electronic musical instrument encodes one of three possible states of a device such as a switch, utilizing only a single input line from that device. The tri-state encoding circuit includes, in the case of a single-pole, double-throw switch, a first signal source which feeds signals of like frequency and duty cycle, but 180.degree. out of phase to the respective fixed contacts of the switch. A first gating element is interposed between a source of biasing signal and the movable contact of the switch. Second and third gating elements receive control signals from a further signal source, these control signals being of like frequency and duty cycle but 180.degree. out of phase. These second control signals are also of the same frequency as the first control signals, but may have a different duty cycle.

Abstract: A portamento system is disclosed for use with an electronic musical instrument, and particularly with a monotonic keyboard instrument which utilizes master oscillator/divider elements for tone generation. The portamento system utilizes a voltage controlled oscillator, and an oscillator control circuit comprising a unique combination of a phase/frequency detector and a circuit for varying and controlling lock up rate and expanding the frequency range of the system which may be either a ramp and hold circuit or a frequency tachometer circuit. The voltage controlled oscillator is thus locked on to the input frequency from the electronic musical instrument with substantially zero phase and frequency error. The system is capable of reaching the input frequency as slowly or as rapidly as desired and will operate over a wide frequency range.

Abstract: A wireless toy musical instrument, such as a guitar, includes a body member and electronic circuitry disposed within the body for transmitting the output of the musical instrument to a separate receiver such as a standard radio. The circuitry includes an audio section having a sound transducer which converts the audio signal generated by the strings of the guitar to a varying electrical signal comprising either solely a voltage or a combination of voltage and current. The circuitry also includes an oscillator section for generating a carrier signal operating at a predetermined radio frequency, the frequency being set by an LC circuit. The converted audio signal from the transducer is fed into the oscillator, the converted audio signal being combined with the carrier signal. Depending on the type of sound transducer used, a frequency modulation of the carrier signal is effected, either by the change of voltage, or current which is generated by the sound tranducer and applied to the carrier signal.

Abstract: A digital organ or like electronic musical instrument of a real time processing system which produces musical notes by synthesizing weighted square waves and applying them to a digital filter of a transfer characteristic controlled for each square wave. Key information from a keyboard is detected by a key code generator having a key switch matrix in which key switches are grouped into a plurality of blocks. The key switches are scanned for each block and when one or more key switches of the block are closed, the scanning is stopped until after the closure information is sent out as binary coded information to a key code data assignor in accordance with priority. The key code data assignor applies envelope control signals to an envelope generator and an N-degree square wave generator. The envelope generator is a cyclic digital filter whose filter constant is controlled to provide desired envelope waveshape data for input to a multiplier.

Abstract: The musical instrument is of a waveform memory device read out type and comprises a frequency information generator for generating a plurality of sets of frequency informations each set consisting of a subplurality of frequency informations and corresponding to each of the tone pitches of the depressed keys in a keyboard, a selector for selecting one, at a time and one after another, of the subplurality of frequency informations generated by the frequency information generator for each one key depressed, an accumulator for repeatedly accumulating the frequency information selected by the selector to produce an increasing accumulated value, a waveform memory device for storing the amplitude values at successive sampling points in one period of a sine wave utilized to form a desired musical waveform, a comparator for comparing the accumulated value with a preset value and controlling the selecting operation of the selector during the operation of the accumulator.

Abstract: A programmable dynamic filter for use with a time-shared electronic organ or the like includes a filter circuit responsive to a logical state of a control signal for tracking notes generated by the instrument. Means are provided for programming the filter independently of generated notes by selectively adjusting the pulse width of the control signal to achieve desired musical effects.

Abstract: Imitation sounds of musical instruments, especially brass wind instruments, re synthesized by using a pulse generator source driving an AGC amplifier channel having an AGC amplifier and formant filters and a limiter, the gain of the AGC amplifier being multiplicatively controlled by an instantaneously-varying control AGC signal derived from the output of the channel. The AGC signal can also be varied at the AGC point by the signal from a breath-sensing microphone in a whistle or pipe.

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 comprises a waveshape memory delivering out digital value samples of one cycle of a certain waveshape, and a loop circuit including a filter and a shift register. The digital waveshape values read out from the waveshape memory is caused to circulate at a predetermined rate of time in the loop circuit. A waveshape taken out from the loop circuit varies as time lapses, and is utilized as a musical tone.

Abstract: An electronic echo apparatus comprising an input amplifier, an output amplifier connected thereto through a transmission channel, a delay device connected in parallel to said channel, and a feedback path connected in parallel to said delay device, characterized in that said feedback path includes a control means, and in that there is connected to the output of the output amplifier a means for measuring the output signal of said output amplifier, comparing said output signal to a predetermined threshold value and, when said output signal reaches said threshold value, supplying a control signal to said control means for terminating the feedback.

Abstract: A variable filter circuit, especially for synthesizing and shaping tone signals, in which a variable light source is provided which influences light sensitive resistor elements in the filter circuit. The variable circuit, by the use of selector switches, can provide different musical features, such as muted voices, percussion, brass, woodwind and the like, all of which will enhance, for example, existing organ voicing while it is, furthermore, possible to obtain the effect of playing a solo instrument together with organ voicing.

Abstract: In an electronic musical instrument, in particular an electronic organ, comprising a circuit for electrically modifying a musical tone by frequency modulation to provide an ensemble effect. The circuit comprises three series connected shift registers which operate as delay circuits and which are driven by three high-frequency oscillators. The oscillators are driven by three vibrato signals. The vibrato signals are out of phase with each other so that each of the clocks is driven by a differently phased signal. The outputs of the shift registers are filtered and are then recombined either electrically or acoustically or both so that a chorus effect is produced. Additionally, the output of the last shift register in the series combination may be fed back to the input of the first shift register in the series combination to introduce additional phase delay in the audio signal for richer ensemble effects.

Abstract: A digitally controllable amplifier unit and musical instrument amplifier incorporating such a unit. Digital control of the transfer function of a high-gain virtual-earth amplifier is effected by switching input and feedback impedances by means of transistor switches. Digital storage means are used to control the transistor switches.

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 control circuit for controlling an automatic rhythm generating circuit of an automatic rhythm performance apparatus comprises a memory for controlling the rhythm start or stop operation of the automatic rhythm generating circuit by an output state, a rhythm performance control signal supply circuit including a plurality of rhythm performance control switches, and a logic circuit having inputs coupled to the outputs of the rhythm performance control signal supply circuit and to the outputs of the memory and having outputs coupled to the inputs of the memory. The state of signals at the outputs of the rhythm performance control signal supply circuit is variable by the operation of the control switches. The logic circuit causes the memory to be set from one output state to another state in response to a variation in the state of signals at the outputs of the rhythm performance control signal supply circuit.

Abstract: In an electronic musical instrument, such as an electronic organ, the speech characteristics of reed organ pipes are simulated by applying pulses produced by key-actuated tone generators, which pulses are preferably narrow as compared to their repetition frequency, to a low-pass filter, the pass characteristic of which has a relatively sharp knee and a very rapid rate of rolloff, thereby to sharply attenuate the harmonics contained in the pulse which have frequencies above the cutoff frequency. The resultant tone passed by the filter is surprisingly reed-like in character, and by changing the cutoff frequency, reed-like voices of differing properties, imitative for example, of an organ Oboe tone, an orchestral Oboe tone, a Clarinet, a Kinura or a Trompette are obtained.

Abstract: An electronic musical instrument in which a plurality of order pulse generators and a plurality of musical-tone-waveform forming circuits are connected in order to a tone-source-signal pulse generator. Interposed in each of a plurality of circuits diverging from the output terminal of the tone-source-signal pulse generator to the order pulse generators is a pulse-counter circuit which has a variable frequency-dividing ratio. On the output side of the pulse-counter circuit, a frequency-dividing ratio-setting signal-generating counter circuit is provided which generates a signal for setting the frequency-dividing ratio thereof.

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: The musical instrument is of a waveform memory device read out type and comprises a frequency information generator for generating a plurality of sets of frequency informations each set consisting of a subplurality of frequency informations and corresponding to each of the tone pitches of the depressed keys in a keyboard, a selector for selecting one, at a time and one after another, of the subplurality of frequency informations generated by the frequency information generator for each one key depressed, an accumulator for repeatedly accumulating the frequency information selected by the selector to produce an increasing accumulated value, a waveform memory device for storing the amplitude values at successive sampling points in one period of a sine wave utilized to form a desired musical waveform, a comparator for comparing the accumulated value with a preset value and controlling the selecting operation of the selector during the operation of the accumulator.