PURPOSE: To enable persons in different places to sing one song as a duet by sending and receiving voice and control signals mutually between orchestral accompaniment devices by using a communication line.

CONSTITUTION: An amplifier 10 is connected to a communication device 8 and a synthesizing device 9 and the amplifier 10 is equipped with a speaker 11 for outputting a sound and a microphone 12 for inputting a voice. Received image data and various signals are sent to and processed by a CPU 7 and voice information is sent to the amplifier 10 as it is and outputted from the speaker 11. Further, the music of the orchestral accompaniment is outputted from the speaker 11 by converting digital data stored in a storage device 5 into music by the synthesizing device 9 and sending the music to the amplifier 10. Consequently, accompanying information on the name of the music, etc., is set to the opposite device for the duet through the communication line and then the orchestral accompaniment begins to be played; and the voice information is sent and received mutually throughout the performance and duet performance becomes possible between the orchestral accompaniment devices.