Turns out Sweeney Todd needed Tim Burton more than Tim Burton needed Sweeney Todd. The director and the Stephen Sondheim musical, about a British barber who slits his customers’ throats and leaves the bodies for the baker downstairs to use in meat pies, are a perfect match. Perhaps too much so. In a way, this is too easy of a project for one of our most creative filmmakers. Burton could do this sort of thing in his sleep, and there are times during Sweeney Todd when it feels like he has. Fortunately, stars Johnny Depp and Helena Bonham Carter, both singing their ghoulish hearts out, make even those moments entertaining.