PURPOSE: To assist the singing of a singer and enables the singer to freely sing a song by automatically playing a melody part which is not automatically played so far if the pitch of the singing deviates from the correct pitch when the singer sings the melody part according to an automatically played accompaniment part.

CONSTITUTION: A microcomputer 201 performs musical tone generating operation and automatic playing operation by reading automatic musical performance data on the melody part and accompaniment part for an automatic musical performance out of an automatic musical performance memory 207. For 'KARAOKE', the singing pitch of the singer is extracted and the nearest pitch name corresponding to the pitch is found. Then, the pitch name is compared with the pitch name of the melody part of the automatic musical performance data and if the melody pitch of the singer deviates from the correct pitch and both the pitch names are, for example, different by a half tone or more from each other, the melody part of the automatic playing device which is not automatically played so far is sounded for a certain time, e.g. a period of one measure from the next note.