Abstract: An automatic rhythm-pattern accompaniment equipment is disclosed that can automatically stop the full-in rhythm sound superposed on or replacing the accompaniment rhythm sound in synchronization with the beat number determination signal. According to a feature of this invention, the automatic rhythm accompaniment equipment comprises a fill-in circuit synchronized with basic rhythm pattern and fill-in beat number determination circuit, a fill-in rhythm-pattern designation circuit and a fill-in rhythm-pattern generator. Therefore, the stop of the fill-in rhythm is carried out automatically by the electronic circuit in synchronization with the beat number determination signal, although the insertion of it is manually done by the music player. If necessary, the insertion of the fill-in rhythm can be synchronized with the beat number determination signal.

Abstract: Random rhythm-pattern generators have been proposed that can select one of several rhythm-patterns (i.e. pulse trains with different repetition cycles) prepared beforehand, change their playing order, and if necessary change the kind of instrumental musical sounds whenever the beating reaches a predetermined number, in order to produce a random accompaniment rhythm sound. The prior art rhythm-pattern generators played the rhythm-patterns only in a fixed order. Therefore, they had the disadvantage of providing a musical performance which was monotonous. According to this invention, this monotony of performance can be avoided because of the following construction: a random pulse generator supplies output pulses representing plural bits of a binary number to a decoder that in turn supplies an output pulse randomly to designate one of the pulse trains with different repetition cycles.