For the holidays, Tim Burton serves up the sugarplum tale of serial-killing barber Sweeney Todd (Johnny Depp), who slits the throats of his customers and then, with the help of bake-shop owner Mrs. Lovett (Helena Bonham Carter), grinds up the corpses and serves them as meat pies to a salivating if unsuspecting public. What more do you want in a musical? So get prepped, gore addicts — Sweeney Todd, subtitled The Demon Barber of Fleet Street and set in nineteenth-century London, is ninety percent sung. And doing the lion’s share of the warbling is Depp, who has never sung a note onscreen and still has the sand to take on a landmark musical by legend Stephen Sondheim that leaves trained opera stars feeling daunted. A recipe for disaster? You’d think. Instead, Sweeney Todd is a thriller-diller from start to finish: scary, monstrously funny and melodically thrilling. And Depp is simply stupendous. He’s not Pavarotti and doesn’t try to be, but his light baritone has clarity, timbre and emotive power. Depp erases the line between singing and acting, fusing them into something that keeps the movie blazing. Oscar, take note. This Sweeney is a bloody wonder, intimate and epic, horrific and heart-rending as it flies on the wings of Sondheim’s most thunderously exciting score. Burton is a true visionary, and with the help of cinematographer Dariusz Wolski, costume whiz Colleen Atwood and production designer Dante Ferretti he sets a new gold standard for bringing a stage musical to the screen. Burton knows that Sweeney Todd has been sacrosanct in theater circles since its Broadway debut in 1979, starring Len Cariou and Angela Lansbury. He knows that what Sondheim composes is considered holy writ. And yet Burton and screenwriter John Logan (Gladiator) have deleted songs, abridged characters and sliced an hour off the show’s three-hour running time in the name of keeping the tale fixed on Sweeney’s need for vengeance. What’s our boy so pissed about? As a young barber, he doted on his wife and baby daughter. The wife’s beauty attracted Judge Turpin (a superlatively creepy Alan Rickman), a sexual predator protected by the law in the person of Beadle Bamford (Timothy Spall). A trumped-up charge sent the barber to an Australian prison and the judge into rape mode. Fifteen years later, Sweeney is back in London, a shock of white in his hair to match his deathly pallor. Mrs. Lovett, his former landlady, tells him that his wife went mad and took her own life, and that the judge now plans to marry Johanna (Jayne Wisener), Sweeney’s daughter. That’s the setup. In the soaring duet “My Friends,” Mrs. Lovett sings of her love for Sweeney while he declares his passion for his razor (“At last my right arm is complete again”). Sweeney regains his tonsorial rep by defeating Pirelli, a rival barber done to a low-comic turn by Sacha Baron Cohen, and tempts the judge into his barber chair. The two sing one of Sondheim’s loveliest ballads (“Pretty Women”), but just before the barber can put blade to the villain’s throat, Anthony (Jamie Campbell Bower), a young sailor also in love with Johanna, interrupts and sends the judge scurrying. Sweeney snaps, and in his strongest anthem (“Epiphany”) vows to take revenge on all mankind. Cue the corpses and the meat pies, as a beggar woman (Laura Michelle Kelly) sings of a “city on fire.” Burton’s use of blood is impressionistic, not realistic. But the prudes still whine about the R-rated violence. When did we become a nation of wimps? This brilliantly conceived and executed film moves from one highlight to another. The darkly delicious Bonham Carter rivals Depp in using an untrained voice to anchor lyrics to truth rather than showoff technique. She is funny and touching singing “By the Sea,” a number that brings the screen alive with color as Mrs. Lovett imagines the impossible: Sweeney returning her desire. Later, Bonham Carter evokes chills in “Not While I’m Around,” a ballad of devotion she croons to her young apprentice, Toby (the excellent Ed Sanders), just before she arranges his demise. As the film follows its tragic course, Depp scores an explosive triumph. Covered in blood, Sweeney is finally engulfed by his emotions, and Depp finds the character’s grieving heart. It’s a staggering moment in a spellbinder of breathtaking beauty and terror.