The SYNC START button sets the BK-7m so that as soon as you play a note or a chord on your instrument, the selected BK-7m rhythm will start to play.
Each time you press the SYNC START button changes the manner in which SYNC START functions.
If the SYNC START button is NOT lit, Sync Start will not be active
If the SYNC START button is lit RED, a rhythm will begin to play as soon as you play a note or chord on your instrument. It will continue to play as you change chords. To stop the rhythm, press the START/STOP button.
If the SYNC START button is lit GREEN, a rhythm will begin to play as soon as you play a note or chord on your Instrument. As long as you hold down a note or chord, the rhythm will continue to play. The rhythm will stop as soon are you release the note or chord.