Abstract: An automatic performance device includes a sound signal generation section for generating a sound signal, a loudspeaker for sounding the sound signal generated by the sound signal generation section, percussion instruments constituting a scale, a percussion instrument drive section for sounding the percussion instruments, a percussion instrument performance information output section for outputting percussion instrument performance information in synchronism with the sound signal, and a converter for converting the percussion instrument performance information to a corresponding drive signal of the percussion instrument drive section. An atmosphere of a live performance is produced and a rich and powerful musical performance as an orchestral performance can be simultaneously made as an accompanying music in a simple manner.