Okay, silly question, but I've never played in an orchestra before. At the dress rehearsal, are you generally expected to actually wear your concert clothes (as actors in a play would do with their costumes) or not?

Thanks,
Bill

Dress rehearsal just simply means that the band will run the entire show as if it were the real thing. Just dress comfortably unless you plan on wearing something that's distacting or you have to maneuver around... or both.