Abstract: A tone generator system for an electronic organ which is capable of being fabricated into an LSI structure and receives a saw-tooth wave or staircase wave as an input thereto comprises a frequency divider for the saw-tooth wave or staircase wave including a ladder resistor network and a complementary MOS FET devices, an analog switch having a wide dynamic range and a high linearity in input-output transfer characteristic constructed by MOS FET devices to serve as an indirect keying means, a sustain means including a novel structure of a variable impedance element which is constructed to control a channel current in a MOS FET device by varying a potential distribution in a source region, and an impedance converter constructed by complementary MOS FET devices and free from a D.C. level shift. With the above arrangement a tone generator system of high quality for an electronic organ is provided.

Abstract: An electronic musical instrument has a plurality of tone selectors which select musical tones; a waveshape calculator which calculates a waveshape represented by amplitudes at two or more than two sampled points of one period of the selected tone and which is operative whenever the tone selectors are actuated; a plurality of waveshape memories which temporarily memorize the calculated waveshapes; clock signal generator which generates clock signals with high frequencies corresponding to pitches of depressed keyswitches of the musical instrument and which is operative whenever the keyswitches are depressed; a reading circuit which repetitively and successively reads out the memorized waveshape amplitudes by the clock signal generated by the clock signal generator; and a converter which converts the waveshape amplitudes read out by the reading circuit to a musical tone, wherein a musical tone is generated by repetitively reading out the temporarily memorized musical waveshape.

Abstract: The present invention is an integrated circuit for an electronic musical instrument comprising: a plurality of frequency divider chains receiving a plurality of input signals for dividing the frequencies of the input signals one after another and corresponding to a plurality of series of adjacent notes which are chromatically arranged in turn in a twelve-tone of a musical scale, respectively; keyer-gates for switching on and off the input signals and output signals of the frequency dividers of the frequency divider chains respectively; and adding means for adding at least two output signals of the keyer-gates which correspond to the adjacent notes chromatically arranged to each other, so as to produce output tone signals therefrom, respectively.

Abstract: A tone generator system for an electronic organ which is capable of being fabricated into an LSI structure and receives a saw-tooth wave or staircase wave as an input thereto comprises a frequency divider for the saw-tooth wave or staircase wave including a ladder resistor network and a complementary MOS FET devices, an analog switch having a wide dynamic range and a high linearity in input-output transfer characteristic constructed by MOS FET devices to serve as an indirect keying means, a sustain means including a novel structure of a variable impedance element which is constructed to control a channel current in a MOS FET device by varying the potential distribution in the source region, and an impedance coverter constructed by complementary MOS FET devices and free from a D.C. level shift. With the above arrangement a tone generator system of high quality for an electronic organ is provided.

Abstract: A voice keying system for a voice controlled musical instrument comprising a frequency responding circuit for responding to an input signal of audio frequency and generating a control signal which corresponds to each of a plurality of frequency bands of input signal and also to a plurality of notes of a musical scale, and a tone generator for generating an output tone signal corresponding to each of the notes of the musical scale. The input signal is converted into the output tone signal having a smaller rate of frequency increment than that of the input signal in each of the frequency bands thereof.