PURPOSE: To enable high-order commands to easily perform other processes in parallel to music performance without directly monitoring the music performance by monitoring the music performance by the CD-ROM device and generating an interruption signal which indicates the end of the music performance when the music performance ends.

CONSTITUTION: In a music performance system, the CD-ROM device 1 and a host computer 7 are connected by a data bus 4 which transfers data and a control bus 5 which transfers control information, and an interruption signal line 6 for sending the interruption signal indicating the end of the music performance is provided. The CD-ROM device 1 monitors performance started on receiving a command from a host program 8 and generates the interruption signal to the host program 8 which indicates the end of the music performance from the CD-ROM device 1 at the end of the specified music performance, and the host program 8 receives the interruption signal to recognize the end of the music performance, and moves to a performance ending process.