Keyboard type automatic accompanying system

Abstract

A keyboard type automatic accompanying system wherein information representative of the root note of a chord and the type thereof are detected from key depression signals assigned by depressing a plurality of desired keys of an accompanying keyboard, the detected information are stored, and an automatic chord complying with the particular chord are accompanied. A chord detector comprises in combination a shift register which stores the accompanying key assignment signals therein and which shifts the stored contents cyclically, and a ROM device in which binary information indicative of the basic forms of chord names and the types of chords are stored. Outputs of the shift register are applied to the ROM device, and the type and the root note of the chord are detected in one shift cycle of the shift register, so that the circuit arrangement is simplified, that the detecting time is shortened and that the key response rate is enhanced. On the basis of the information representative of the root note of the chord and the type thereof, an auto-chord tone assignment signal is formed by an ACC signal generator. The signal is timed in a chord tone generator by a rhythm pulse transmitted from a rhythm pulse generator, and becomes an automatic chord accompanying tone signal. The tone signal is amplified by an amplifier and provided as an output by a loudspeaker.