It's no wonder that Sondheim was drawn to "Sunset Boulevard." The story of a queen without a crown is also the story of "Gypsy." But "Gypsy" doesn't end with a blood bath -- and Sondheim accepted Billy Wilder's argument that "Sunset" is really an operatic tragedy, not fit for a Broadway stage. (Unless "Sunset" is a comedy? One critic observes that a comedy ends with the protagonists getting what they want. Norma wants a closeup--and Joe wants a swimming pool. Both dreams are fulfilled.) The biggest treat in David Lubin's new book is its discussion of Billy Wilder. As a child in Vienna, Wilder learned that his father had a secret family; this was never "brought to the light." Wilder had a talent for storytelling but not for the English language--so he began listening obsessively to radio dramas. He wanted to train himself. Then, the dazzling highs: "Ninotchka," "Double Indemnity," "The...