Digital arpeggio generating device

Abstract

An arpeggio circuit for an electronic organ employing digital encoding, decoding and code conversion techniques to semiautomatically generate an arpeggio effect composed of tone signals having an octaval relationship and corresponding to selected note keys held down on an accompaniment keyboard. The rate of generation and order of the arpeggio tone signals is controlled by means of a plurality of manually actuatable arpeggio control switches. A plurality of individually identifiable control signals are sequentially generated in response to sequential actuation of the plurality of control switches. The control signals are binarily encoded. Tone signals provided by a set of tone generators are selectively associated with appropriate ones of the encoded control signals by a tone selector circuit which provides the selected one of the tone signals to an arpeggio output tone signal generating circuit when the associated encoded control signal is being generated. An octave select circuit of the output circuit selectively generates an output tone signal at a selected octavely related frequency to the selected tone signal in response to the encoded control signal associated therewith. Both the tone selector and the octave selector are responsive to make tone selections for a given control signal depending upon the number of selected notes. The encoding of the control signals is accomplished by a single decoder which develops decode control signals for controlling both the tone selection and octave selection. The decoder is alternately employed by both an automatic arpeggio and the manual arpeggio circuit. When used by the manual arpeggio circuit, a code converter alters the input codes to the decoder so that an output arpeggio tone signal is generated in response to actuation of each of the control switches.