A set of MIDI data codes defines time intervals each between two events successively to occur, and lapses of time from initiation of playback are stored in a set of audio data codes read out from a music compact disc, wherein a data synchronizer converts times at which the events to occur to lapses of time from the initiation of playback so as to transfer the MIDI data codes to a musical instrument synchronously with the playback through a compact disc player, thereby playing a piece of music in ensemble between the musical instrument and the compact disc player.