Tonight I’ve been re-listening to something I haven’t heard from music collection in a while, Michal Tilson-Thomas’s recording of Aaron Copland’s three American-ish ballets, “Billy the Kid,” “Appalachian Spring,” and “Rodeo.” All with the San Francisco Symphony. These are, of course, among the most performed American works, and these recordings from a few years ago are among the best. Perhaps only Leonard Bernstein (who was MTT’s mentor) does them as well.