SWEENEY TODD. Music and lyrics by Stephen Sondheim, book by Hugh Wheeler, based on the play by Christopher Bond; directed by Harold Prince; scenery by Eugene Lee; lighting by Ken Billington; costumes by Franne Lee; orchestrations by Jonathan Tunick; with Angela Lansbury, George Hearne, Ken Jennings, Edmund Lyndeck, Chris Groenendaal, Betsy Joslyn, Sal Mistretta, Angelina Reaux, Calvin Remsberge and (performing for Lasnbury at Wednesday matinees) Denise Lor.

At the Kennedy Center Opera House through Nov. 29.

"Sweeney Todd" ran for a year and a half in New York, generated nightly standing-screaming ovations, won every imaginable award for its creators and stars, and helped make Broadway credible to a new and justly suspicious generation of theatergoers. And it did all those things under abominable circumstances -- in a huge airplane hangar that pretends to be a theater, where the acoustics were more nonexistent than bad.

So if you missed "Sweeney Todd" on Broadway, stop fretting and get moving. Saturday night at the Kennedy Center, this incredible production was seen for the first time as it should be seen. You may have qualms about the sotry or the view of the world conveyed by composer/lyricist Stephen Sondheim and director Harold Prince, but this is a show that will knock you over and trample across your remains like a tank battalion. In this unusually -- perhaps uniquely -- uncompromised touring production, Sondheim's mesmerizing score is richly audible from the mouths of a cast that, no longer struggling to be heard and seen, is liberated to sing and act to its full potential.

And the full potentials of George Hearn and Angela Lansbury are something to behold. As the throat-slashing barber, Hearn has a far stronger voice than Len Cariou, the original Sweeney, and he brilliantly suggestes the boundless inner malice of the man who, "back of his smile, under his word . . . heard music that nobody heard." His performance is also a Guinness-record-caliber triumph of the human larynx, straining, shouting and scratching for almost the whole two-hour length of the show.

As Sweeney's meat-pie-making accomplice, Lansbury is a vertiable new woman in the friendlier environment of the Opera House. Not that there was anything so wrong with the old Lansbury, but it's hard to appreciate the small touches in a performance when the body is standing in one place and the voice seems to be somewhere else entirely. Here, Lansbury is a total delight from the moment of her sensational introduction, boasting of the "Worst Pies in London" and denying the rumor of cat meat in her recipe. "Just the thought of it's enough to make you sick," she sings, "and I'm telling you them pussycats is quick."

Through all the atrocities committed on her premises, Lansbury's Mrs. Lovett -- an openhearted but utterly selfish creature -- permits herself only one moment of apparent moral outrage. This is when Sweeney slashes his first throat, that of his pseudo-Italian competitor, Signor Pirelli. But when Sweeney explains how Pirelli had tried to blackmail him, Mrs. Lovett's response is: "Oh, well, that's a different matter." And her doubts are instantly lost in speculation about how Pirelli's remains might profitably be utilized.

The Sondheim/Prince "Sweeney Todd," their fifth collaboration in a decade, arose from a "penny dreadful" serial and a stage melodrama of the 1840s -- both about a barber who slit his patrons' throats and shipped the bodies (through a kind of laundry chute) to a woman who turned them into meat pies. In 1973, British play-wright Christopher Bond rewrote the legend as a tale of revenge, with Sweeney transported to Australia by a judge who had coveted his wife, then returning to London to wreak revenge 15 years later. And Bond's version became the springboard for Sondheim and Prince's "musical thriller."

The story, of course, is not the normal stuff of Broadway musicals -- or never would have seemed so until Sondheim applied his phenomenal musical and lyrical imagination to it. Who else would have thought to have a barber sing a love song to his razor? And who else could have written the marvelously intricate, pun-crazed "A Little Priest," Lansbury and Hearn's duet about the advantages of human meat in the pie business -- including the prospect of "shepherd's pie peppered/with actual shepherd." Or, as Lansbury sings: "If you're British and loyal You might enjoy royal Marine. Anyway, it's clean. Though, of course, it tastes of wherever its been."

"Sweeney Todd" has next to no book, but Hugh Wheeler, who contributed what there is, deserves a share of the credit for the leanness and steely efficiency of this production. Prince deserves a larger share -- for the innovative blending of scene changes into the action, with actor/stagehands rolling, revolving and unfolding the various scenic elements, all the while singing elaborate choral bridges and commentaries, then freezing into the darkness as the story resumes.

Dickens and Hogarth are the inspirations for the mood and look of the show, and the stark lighting (by Ken Billington) and factory-carcass set (by Eugene Lee) are the keynotes of that look. The use of garish white follow-spots (manned by visible lighting men in the rafters) gives the audience the feeling of scouring a dark, rat-infested basement with a flashlight -- or of catching momentary, isolated glimpses into the grimness of 19th-century industrial England.

Yet in Dickens and Hogarth, there was a rich feeling for the common humanity stifled and reduced by the corruption, exploitation and bureau-cratization of their day. The savage eye of Sondheim and Prince seems at its most savage, oddly, when it is trained on ordinary, good-natured people. Hence, the young lovers -- particularly Sweeney's daughter Johanna with her rag-doll wig -- are as distasteful as the villains (and not nearly as interesting).

When the plot turns to Johanna or Anthony (the sailor who has rescued Sweeney and fallen in love with his daughter), Sondheim's imagination seems to stop flowing. But if he has ducked the challenge of writing evocatively about romatic love, at least he has a good alibi in having modeled his work on 19th-century melodrama, with its similarly one-dimensional treatment of such matters. And he has another, even better alibi in having written the most riveting and original American musical in years.