PURPOSE: To easily synchronize an automatic performance with an external performance irrespectively of the technique of a player.

CONSTITUTION: With a pattern specification key 2 (P1-P7 or K1-K3) depressed, performance information corresponding to a current pattern painter is read out of a pattern memory at a speed corresponding to the generation intervals of tempo pulses and a specified rhythm pattern is generated to play music. At this time, the tempo and timing (absolute beat position) of the automatic performance can easily be varied in sequence by depressing tapping keys (3) K1 and K2 for inputting the tempo and timing. A beat position specifying function like this is displayed to easily match the timing of the automatic performance with the external performance and a dynamic adjusting function for the tempo is displayed to match the tempo of the automatic performance or a rhythm pattern performance.