A telephone terminal device such as a portable telephone performs music playback processes with respect to use-specified music data in which tempos, tone colors, and pitches are specifically processed to suit different uses while tone color assignment and musical score are commonly shared among different uses, or common-use music data that are partially modified to suit a specific use in reproduction such as production of incoming call melody sound, hold sound, background music (BGM) during conversation in progress, karaoke accompaniment sound, and music for appreciation.