Michael Cerveris gives the performance of a lifetime in the title role, one all the more potent because of the production's bare-bones simplicity. With next to no scenery to distract you -- not even a barber's chair -- it's easy to lose yourself in the mad intensity of his demonic stare. Mr. Cerveris, whose head is as smooth as a cue ball, looks like an apostate monk on the prowl, and when he proclaims that "they all deserve to die," you know he means to slit every throat within razor's reach. As for his partner in crime, Ms. LuPone has transformed herself almost beyond recognition into a sewer rat in a skirt. Her lower-lower-class accent is flat and vicious, her singing (aided by some discreet transpositions) bitingly clear. I've never seen or heard a scarier Mrs. Lovett, and don't expect to.

A Compelling Ensemble Cast

If Ms. LuPone and Mr. Cerveris were all this "Sweeney Todd" had to offer, it'd still be worth paying a hundred bucks to see. Instead, they are part of a totally committed and compelling ensemble cast whose less well-known members deserve much wider recognition (Broadway debutante Lauren Molina, for example, is perfect as Johanna). That they play their own instruments is amazing enough in and of itself. That they play them well enough to bring to life Sarah Travis's ingenious reorchestration of Mr. Sondheim's demanding score is… well, I can't think of a sufficiently warm adjective, though I also want to praise the rhythmic exactitude of their singing. That's what you get when you cast actor-musicians with instrumental training, then make them sing and play the whole score from memory.

Far more important, this device, dreamed up by Mr. Doyle for the production's original English run, is not a gimmick but an indispensable part of his directorial concept. To be sure, tradeoffs are inevitable in so drastic a stripping-down of an essentially operatic show. While much of Mr. Sondheim's score is similarly intimate in scale, the climaxes lack the overpowering effect that can only be supplied by a full orchestra and chorus. In addition, the presence of so many instruments on stage occasionally causes visual clutter, though Mr. Doyle, who doubled as the show's designer, usually succeeds in making them integral to the staging (it's a neat touch, for instance, that Johanna and Anthony, her young suitor, both play cello).

So no, this isn't the only way to perform "Sweeney Todd," or even the best one -- but when you're sitting in the theater watching this cast, you won't want to be anywhere else in the world. In fact, I liked it so much that I've already bought tickets to see it again on my own dime.