The thing to remember is that in general, unless you're playing for a rehearsal rather than a class, the participants don't actually care what you play. You're only there to help them keep in time. One company I know does class with a drummer rather than a pianist. So - really, play what you like, have fun, and don't bother learning anything difficult unless you want to learn that piece for its own sake.
Same way with their meals: a hot meal is a cup of coffee and a cigarette.