Stephen Sondheim: The Story So Far (Sony Classics, four CDs). Eighty-two songs by the greatest musical-theater composer of the postwar era. All of Sondheim’s shows are represented, and the performances range from original-cast recordings to rare demos sung and played by the composer himself. Sondheim fanatics will already have the bulk of this material, but if you’re just getting to know him, The Story So Far is a good place to start (TT).