MUSICAL / A really close shave: Paul Taylor reviews the National's Sweeney Todd

WHEN Sondheim's Sweeney Todd first hit London 13 years ago, the design was in danger of upstaging the musical. Gazing at the huge iron gantries and mobile walkways of Eugene Lee's set, you kept thinking, 'Great, but when is the big chase scene?' It never came. Like all subsequent English productions, this spare, razor- sharp London revival by Declan Donnellan, in the Cottesloe, draws the audience into more intimate contact with the Grand Guignol grisliness and unsavoury farce, the throat slittings and the greedy, incognisant scoffing of human pies. The seven-strong chorus hold the flesh out on forks, temptingly, the public's proximity to the action rendering it a sitting target for the musical's accusatory, quasi-Brechtian stabs at social critique.

Indeed, people in the stalls may become conscious that, as they look up to the high platform where Todd's tonsorial parlour is positioned, they tilt their heads back in just the manner of his victims in the barber's chair. In a touch typical of the simple, fluid and, at times, dreamlike clarity of the staging, the perverted Judge (excellent Denis Quilley) who is the focus of Todd's revenge delivers a sentence of death on some poor youth while enthroned on this seat of his eventual undoing. Throughout, Donnellan uses the chorus as a key presence, having them cluster round Todd and lay supportive hands on his shoulder. Eerily, they persist in seeing him as a mythic hero and conveniently ignore the fact that in the course of his revenge on corrupt society, innocent folk are as likely as the wicked to end up as pie-filling.

Obsession, rather than social injustice, is the theme that most animates this work and Sondheim's superb score. To take one example: returning to London after 15 years in enforced exile, Todd discovers that his wife has been driven to her death and his daughter made a ward of court by the evil Judge. In a brilliant stroke to indicate the onset of abnormality, Sondheim has him displace his affections, singing a rapt song of loving reunion to the gleaming blades of his old razors. His intense absorption (so much more disturbing than rant) is reinforced by the fact that he doesn't even notice the parallel outpourings of Mrs Lovett, the pie-shop owner who is equally monothematic about him.

Alun Armstrong occasionally sings out of tune and lacks any of the sexual charisma that would make Mrs Lovett's long- standing crush plausible (which was not the case when Quilley played the part). He's an excellent actor, though, and with that knobbly face lit up with a sickly, brooding monomania, he has no difficulty in keeping you gripped. Among a strong cast, Adrian Lester is in beautiful voice as the young romantic sailor, and Barry James makes a strikingly repulsive Beadle. Definitive is the only word to sum up Julia McKenzie's Mrs Lovett. Under a cockade of green feathers that looks like a neglected pot plant, she gives a hilarious, chilling demonstration of a woman who'd like to think she was a respectable, sentimental old softie, at heart, even while running a human pie shop. Gizzard slittin' good.