It's 19th century London and everyone is singing, but when arterial blood sprays from the opened throat of Signor Adolfo Pirelli, you know this is no "My Fair Lady."

Stephen Sondheim's award-winning musical "Sweeney Todd: The Demon Barber of Fleet Street," a savage tale of cannibalism, madness and serial murder, is now Tim Burton's "Sweeney Todd." The show couldn't have fallen into better hands. With realistic gore replacing the stylistic bloodletting in the stage version, "Sweeney" loses some of its darkly comic tone -- not a lot of laughs here except the nervous kind.

More akin to Burton's "Sleepy Hollow," where heads rolled like so many bowling balls, his "Sweeney Todd" places its emphasis on Grand Guignol and the deeply human story of twice-lost love and the horrifying destructiveness of revenge.

It took two studios, DreamWorks and Warner Bros., to share the considerable risk of making and marketing this tragic tale that defies so many conventions of the American musical. It will be a significant challenge to find a substantial audience despite the advantage of the Burton and Sondheim brands along with a cast that includes Johnny Depp, Helena Bonham Carter and Sacha Baron Cohen.

"Sweeney Todd" comes from an obscure British melodrama -- which might or might not have been based on true 18th century events -- about a deranged barber who slit the throats of customers and his landlady who served the victims up in meatpies.

Sondheim's 1979 show took place within the context of the Industrial Revolution and its rampant corruption and avarice. More satiric opera than musical, "Sweeney Todd" blended together a number of theatrical and literary modes, making the show at once Brechtian, Dickensian and Jacobean. Sondheim acknowledges the influence of the film music of Bernard Herrmann even as he throws in a Viennese waltz or music hall burlesque.

Burton and writer John Logan take all this as a gift, which is then filtered through Burton's own unrepentant sense of the macabre. Except for imaginary sequences or flashbacks to happier days, the film has a monochromatic look with color drained from cityscape. Depp and Carter dress mostly in stark dark clothes with black circles around the eyes, almost as if the figures in Burton's "Corpse Bride" served as models.

In choosing actors who can carry a tune as opposed to singing-actors, Burton has wisely gone for the tragic, emotional heart of the story, narrowing the focus to Sweeney; Mrs. Lovett, the meatpie lady, plagued by unrequited love for Sweeney; and Toby (Edward Sanders, who has a striking voice), the street urchin who assists but is innocent of the pie's ingredients.

Depp is the movie's heart and guts. His Sweeney, nee Benjamin Barker -- having escaped false imprisonment in Australia after 15 years -- is ruled by revenge upon his return to London. Presented with his razors, which Mrs. Lovett (Carter) has lovingly guarded all these years, he grasps a blade with his firm right hand. "At last, my arm is complete again," he thunders.

His homicidal rage centers on Judge Turpin (a dour Alan Rickman), a vile sexual predator who had Benjamin arrested by henchman Beadle Bamford (a smarmy Timothy Spall) so he can steal Benjamin's wife (Laura Michelle Kelly) and baby daughter. Sweeney learns that his wife poisoned herself and Turpin, who took the baby as his ward, lusts after the now grown woman Johanna (a wan Jayne Wisener). Anthony (Jamie Campbell Bower), a young sailor who rescued Sweeney at sea, now longs to do likewise for Johanna on land.

Thus, a triangle of obsessed characters emerges. Depp plays Sweeney as a man so focused on death, so committed to blood, that he has lost all touch with life. Carter's amoral Nellie Lovett, her hair apparently combed with an egg beater, is herself obsessed with Sweeney. She imagines an impossible life with him without realizing he is unmoored from any reality in which this might take place.

The judge, hungering after young women, is the film's major disappointment. Onstage, the tormented man struggled with his obsession, longing to regain his goodness. Here he is a stock melodramatic villain who lacks any ideals other than those of self-interest, though Rickman uses all the tricks in his actor's bag to coax a human being out of the caricature.

Sanders' Toby is a street kid who turns out to possess a moral compass the adults so sorely lack. Baron Cohen as Pirelli, the barber's first victim, is surprisingly muted. Perhaps the requirement to sing has neutralized Cohen's usual outrageousness. Burton doesn't seem to know what to do with film's ingenues, Wisener's Johanna and Bower's Anthony, so they are largely ignored.

The musical numbers ooze with Sondheim's audacious wit and scathing lyrics. A lullaby conveys menace. A waltz celebrates conspiracy. Cynicism runs through all the songs' social critique.

The blood juxtaposed to the music is highly unsettling. It runs contrary to expectations. Burton pushes this gore into his audiences' faces so as to feel the madness and the destructive fury of Sweeney's obsession. Teaming with Depp, his long-time alter ego, Burton makes Sweeney a smoldering dark pit of fury and hate that consumes itself. With his sturdy acting and surprisingly good voice, Depp is a Sweeney Todd for the ages.

SWEENEY TODD: THE DEMON BARBER OF FLEET STREET
DreamWorks/Paramount
DreamWorks and Warner Bros. Pictures present a Parkes/MacDonald/Zanuck Co. production
A Tim Burton Film
Credits:
Director: Tim Burton
Screenwriter: John Logan
Based on the stage musical by: Stephen Sondheim, Hugh Wheeler
Music-lyrics: Stephen Sondheim
Producers: Richard D. Zanuck, Walter Parkes, Laurie MacDonald, John Logan
Executive producer: Patrick McCormick
Director of photography: Dariusz Wolski
Production designer: Dante Ferretti
Co-producer: Katterli Frauenfelder
Costume designer: Colleen Atwood
Editor: Chris Lebenzon
Cast:
Sweeney Todd: Johnny Depp
Mrs. Lovett: Helena Bonham Carter
Judge Turpin: Alan Rickman
Beadle Bamford: Timothy Spall
Signor Adolfo Pirelli: Sacha Baron Cohen
Toby: Edward Sanders
Johanna: Jayne Wisener
Anthony Hope: Jamie Campbell Bower
Running time -- 116 minutes
MPAA rating: R