To provide a mobile karaoke system composed of a small sized mobile karaoke device by which a karaoke music piece is reproduced with high sound quality, and a stationary karaoke device connected to the mobile karaoke device.

The mobile karaoke device 2 stores MP3 compressed karaoke performance sound, and reproduces the karaoke performance sound by expanding it. The mobile karaoke device is connected to the stationary karaoke device 1. When a user requests the karaoke music piece by connecting the mobile karaoke device 2, this music piece is performed by using a musical sound synthesis section 12 and an effector 13, and output from a speaker 17, and thereby, the user can sing. The simultaneously synthesized musical sound is recorded and MP3 encoded, and it is written in the mobile karaoke device 2. Lyrics information is also included in this MP3 data. Thereby, karaoke performance is attained by the mobile karaoke device with the same sound quality as the stationary device.