Say this much for Damien Chazelle: He shows his audience exactly what he's giving them within the first few minutes of "Babylon," his bruised, black-eyed valentine to Hollywood's sybaritic heyday. In a whopper of an opening number, Chazelle films the delivery of an elephant to the estate of film producer Don Wallach (Jeff Garlin), a bravura scene of extravagance and excess that ends with not a few bit players covered in pachyderm waste - recalling the famous joke about the guy who cleans up after the circus every day. Asked why he doesn't quit, he replies with incredulity: "What, and leave show business?"