Its happened the last two nights: In the middle of a song, the bass note of one chord kept playing even after I went to the next chord of the song.

The first time it happened, I turned off the unit and it corrected when turned back on. Last night, when it happened again, I, quickly, turned the Accomp button off and on without stopping the song. That also worked.

Any clues as to what might be wrong or needs to be checked?

Eddie