Thanks for your reply!
I forgot to mention that I'm using the SD 1. Software version 3.0 B.
I can't distinguish the difference between the Programs feature and the One Touch (manuals are not my strong point), but it seems that the One Touch 'palette' is constant, regardless of the Registration I'm using.
I had been calling up the drum patterns using the keypad and frantically changing instrument during each song. Having better access to the voices relevent to the current Registration would make things much better.