Abstract: A keying system for an electronic musical instrument incorporates time division multiplexing of the individual frequency component signals which are combined to synthesize musical notes or tones. A signal generator provides the fundamental and various harmonic frequency signals which are applied to a plurality of multiplexer circuits corresponding in number to the number of keys on the keyboard of the musical instrument. Activation of a key connects the multiplexer output signals from a corresponding one of the multiplexer circuits to a demultiplexer circuit on a common bus. Time slot signals control the multiplexers and demultiplexer to generate the desired tones corresponding to activated keys.

Abstract: An electronic sound generation system wherein an input signal is frequency modulated, and the modulated signal passes through a series of cascaded shift registers. Amplifiers are provided for compensation of insertion loss in each shift register stage, and a frequency modulation detector is utilized to produce the time-delayed output echo signal.

Abstract: A programmable rhythm apparatus for use with an electronic musical instrument comprising a sequential pulse generator, a plurality of individually programmable rhythm channels or tracks each producing an output pulse pattern in response to the sequential pulse generator and a standard voice generation circuit to receive the pulse output pattern from the programmed rhythm channels. The voice generation circuit produces a signal representative of an unpitched musical instrument with a rhythm pattern corresponding to the pulse output pattern of an individual rhythm channel. The voice generation circuit output signals corresponding to each rhythm channel and representing different unpitched instruments are combined and applied to an audio transducer. Each individual rhythm channel can be programmed by the instrument player to provide a pulse output sequence representative of any rhythm pattern desired. Each rhythm channel has a plurality of logic means and a selection means.

Abstract: A tempo setting device for use in an automatic rhythm instrument comprising a control means actuatable repetitively by the instrument player to produce a plurality of signals at a rate corresponding to a desired tempo and a circuit means responsive to the signals to produce a control signal related in magnitude to the rate. The control signal is applied to a voltage controlled tempo oscillator which is part of the automatic rhythm instrument and has an output frequency determined by the magnitude of its input signal. Thus, by actuating the control means at a rate corresponding to the desired tempo, the instrument player can regulate the tempo of the automatic rhythm instrument.