I haven't had my Audya 4 long enough to set anything up yet to use the up/down foot switch, but on my MS40 I had sometimes 2 or 3 voices I would change back and forth with for a particular song and I would save them consecutively in either user voices or programs and the first one would be called up with a registration. Then I could use the foot switch to move up or down as desired while playing. Also worth mentioning, the up down foot switch will change voices, but will also change programs if that button is "on", and same with registations if that button is "on"

gary