Neither Tim Burton nor Stephen Sondheim cares much for American movie musicals. In Burton’s case this isn’t surprising or particularly interesting. He says he considers them too “campy,” and he’s got a point.

Sondheim’s reservations are more intriguing and they have substantial relevance. Burton has directed the film version of the eminent composer’s renowned musical drama, Sweeney Todd, with Sondheim’s enthusiastic approval and assistance. That Burton and his colleagues dismantled and altered large sections of the show doesn’t bother him, he has said repeatedly, because that’s what was required. For Sondheim, filmed stage musicals are leaden and stagey; there’s too much stopping for the numbers. The requirements of these media are too opposed to each other. I think his objections are overstated, but it’s true that this is the most successful of the five movies made from Sondheim shows.

Sondheim and playwright Hugh Wheeler took off from Christopher Bond’s mid-1970s reworking of a venerable gothic English melodrama that appeared about 170 years ago. Burton had long wanted to have a go at their musical, and Sondheim agreed to let him try over a decade ago.

Sweeney is the grotesquely violent, melodramatized tale of Benjamin Barker (Johnny Depp), a young married barber in London who is arrested on trumped-up charges and sent off to a penal colony in Australia because an evil judge named Turpin (Alan Rickman) covets Barker’s beautiful wife. Upon his escape and return 15 years later, Barker, now Todd, discovers his wife has died and his daughter has disappeared. The savagely vengeful Todd forms a partnership with a bakeshop owner, the widowed Mrs. Lovett (Helena Bonham Carter), to use the customers whose throats Todd cuts as filling for her meat pies (butcher shop prices being what they are, as the very practical Mrs. Lovett observes). Meanwhile, the barber waits to get at Turpin.

To convert the show into cinematic terms, Burton and screenwriter John Logan (co-writer of Gladiator) have made major alterations. They’ve shortened it by around one-third; jettisoned much of Sondheim’s score—with his cooperation; added some material and repositioned and reworked some other scenes. Even that signature song, “The Ballad of Sweeney Todd,” has been dropped, along with the chorus that sang it.

The result is a motion picture with a tighter, more propulsive narrative than the stage show, a tenser more quickly moving work.

It’s at once more naturalistic and stylized in an expressionistic manner. This visual embellishment is scarcely surprising in a movie by Burton, a director for whom design has sometimes trumped story lines. The look of the film—which was photographed by Dariusz Wolski and designed by Dante Ferretti—is vaguely reminiscent of the almost stygian atmospherics in Burton’s two Batman films. The chromatic range of much of what we see is dominated by gray and dun tones.

Burton’s Sweeney works on its own terms, and much of the original is still there, but it also has its own limitations. The casting was another departure. Sondheim’s show was conceived as an operetta and it has been staged by opera companies. Large portions of its story are performed in song, but neither of the movie’s two principals is really a singer.

The modest revelation is how well Depp acquits himself musically. His voice is limited, and it’s a little nasal, like a lot of rock singers’ (and he once was one), but he can use it melodically and muster some feeling in his singing. Carter’s vocalizations are another matter. They’re something of a drag on the proceedings, thin and forced. She sometimes winds up at the end of a line in a kind of wheezing squeak. Her duets with Depp are aurally and dramatically out of balance. The slyly macabre patter of “A Little Priest,” in which this grotesque twosome consider the commercial possibilities of cannibalism, comes across better because its vocal demands are modest. But the best duet pairs Depp with Alan Rickman as they join together in “Pretty Women,” a lulling air that points up the mounting wave of dread propelled by Todd’s intentions.

Depp is an artful actor who can create amusing, even striking effects. He has a well-known penchant for the fey and the quirky, but he’s never been a compelling performer. Playing Todd may be the biggest acting challenge of his career. His creative response is no failure, but he doesn’t really command scenes with the demonic dimension and tragic undercurrent that Sondheim and Wheeler aimed for. This Todd is more sullen, glowering and cunning than furiously maniacal. Burton and Depp have rendered him a little smaller. He looks a little too much like a 19th-century romantic figure, rather Byronic. (And the silly white streak in his hair recalls Elsa Lanchester in Bride of Frankenstein, or perhaps Lily Munster.) Vocal restrictions aside, Carter delivers a perfectly appropriate Mrs. Lovett, almost a poignant slattern with middle-class domestic aspirations in the midst of the gory mayhem.

Burton’s transfer of Sondheim’s show has considerable virtues and rewards, not least in its ominous atmospherics and tense energy. It works most of the time. If it lacks the schizzy moral undertones and striving for the tragic of the original, it’s by no stretch a botch-job. And as Sondheim himself has said, you can go back to the original and its score for whatever is missing.