BY BOB STRAUSS >FILM CRITIC

It's been a great year for what could be called anti-musicals at the movies. "Once," "Across the Universe," "Romance & Cigarettes," even "Hairspray" in its way, broke many of the genre's conventions, and by doing so revitalized the form.

Now comes Tim Burton's film of Stephen Sondheim's revolutionary stage show "Sweeney Todd: The Demon Barber of Fleet Street." It's as innovative in its way as the gory period melodrama was when it first hit Broadway in 1979. I can't say that all of Burton's new ideas about presenting a blood opera on film are successful, but most of them have an active intelligence behind them.

And when anything else fails, we have arterial sprays for the ages to fall back on.

The director's main experience with production numbers comes from the stop-motion shows ("Nightmare Before Christmas," "Corpse Bride") he didn't entirely direct and a few bits in "Charlie and the Chocolate Factory." Understandably, then, he called on good pal Johnny Depp and gal pal Helena Bonham Carter to help him through this primarily sung horror fable. Neither actor is a trained vocalist, but what they don't have in lung prowess lends a welcome vulnerability to the revenge-minded throat slitter and, particularly, to his partner in crime Mrs. Lovett, who makes delicious meat pies out of the remains of his victims. They both acquit themselves well with Sondheim's tricky and voluminous lyrics.

Burton risks tedium throughout the first act, which consists mostly of Todd and Lovett statically singing back story to one another following his return to a grimy, color-desaturated, mid-Victorian London after 15 years' false imprisonment in Australia. There is a certain wisdom to keeping the camera of Dariusz Wolski (he shot Depp in all of those pirate movies) locked down at this point, and letting Dante Ferretti's Gothic production design do most of the visual talking. But it doesn't quite click, and that's partially because Depp's facial expressiveness is limited by heavy makeup - dark eye circles that seem to cover half his face, the rest of which looks slathered in ashen plaster, and a rigid swept-back mane with a distracting, Bride of Frankenstein white streak. He stalks through the movie with a perpetual, single-note scowl.

Things start moving better with the appearance of Sacha Baron Cohen's rival barber and unwitting meat pie inspiration Pirelli. Ol' Borat gets the dark humor of the piece perfectly, and once the blood starts flowing, Burton grows increasingly comfortable with more fluid, musically matched camerawork and editing.

The second half of the movie builds well to its hysterical, gory climax. But whether you want to interpret it as a grand tragedy of maniacal vengeance or just an exceptionally tuneful and artistically icky horror film is your choice. I lean strongly toward the latter.

But if you're a theater buff, beware. Many of the songs you loved in the stage production are gone or severely truncated.

And that wonderfully dissonant, Bernard Herrmann-esque underscore is performed by a much larger orchestra than you're used to hearing. At times, if you're in a THX-equipped movie auditorium, you'll swear you're hearing old-school, overbearing Broadway melodies, quite the antithesis of Sondheim's signal achievement.

But you know what, purists? Get over yourselves. Sondheim supervised, or at least approved, every musical change for the movie.

Far more often than not, they work better for the different medium.

And I suppose that can be said for just about everything Tim Burton's done with "Sweeney Todd." It's not a great movie musical, but it's a thoughtfully daring and unique one. And nasty good fun, for the most part.

Bob Strauss, (818) 713-3670 bob.strauss@dailynews.com

SWEENEY TODD: THE DEMON BARBER OF FLEET STREET

R: violence.
Starring: Johnny Depp, Helena Bonham Carter, Alan Rickman, Timothy Spall, Sacha Baron Cohen, Jamie Campbell Bower, Jayne Wisener.
Director: Tim Burton.
Running time: 1 hr. 53 min.
Playing: Area wide.
In a nutshell: I'm not sure Tim Burton knows how to make a stage-to-movie musical, but the gore is great in this film of Stephen Sondheim's Victorian blood feast.