Automatic accompaniment device having a function for controlling accompaniment tone on the basis of musical key detection

摘要

A provisional key is determined on the basis of a relatively small amount of performance information (for instance, information on one chord) , while a definite key is determined on the basis of a relatively large amount of performance information (for instance, information on progression of plural chords). If a definite key has been determined, an automatic accompaniment tone is controlled on the basis of the determined definite key, but, if no definite key has been determined, an automatic accompaniment tone is controlled on the basis of the provisional key. The definite key based control is performed in a different manner from the provisional key based control. The definite key based control can achieve control of higher musical quality (for instance, tension notes can be used in a daring manner), but such a daring control is refrained in the provisional key based control.