Sweeney Todd, Trafalgar Studios, London

Stephen Sondheim's gory musical masterpiece Sweeney Todd goes for the jugular with the surest aim when it is presented as an intimate chamber work.

This wonderfully fresh and fierce, small-scale version directed and designed by John Doyle, which originated at Newbury's Watermill Theatre, has landed in London for a run at the Trafalgar Studios.

This production kicks off with the Demon Barber's creepy resurrection from a coffin that remains centre-stage. Dispensing with a detailed panorama of London, this staging immures us in what appears to be the operating theatre of a Victorian asylum.

Here the story of revenge and insanity, mass murder and its cannibalistic by-products, unfolds like some endlessly recurring nightmare. Now an inmate in this establishment, the boy Toby, the one mad survivor of the Todd ménage, is released from his gag and straitjacket to become a troubled spectator and participant.

Realism is ditched in favour of a brilliantly expressive symbolic approach. The splendid cast of nine double as musicians, their instruments becoming weird extensions of their characters' personalities, particularly the disturbed flute of Sam Kenyon's excellent Toby.

There is no conventional barber's chair or trapdoor into the cellar: instead, the throat-slittings are registered by a screaming whistle, a blinding red glare, and a bucket of blood tipped into the coffin by some ironically appropriate figure. The fluidity of Doyle's directorial concept allows the characters to configure in dreamlike patterns of psychological association and wish-projection.

The singing is not first-rate, but what the production sometimes lacks in technical finesse, it makes up in atmosphere, ensemble spirit, versatility and acumen.

Karen Mann is very funny as the pie-making Mrs Lovett, a camp old would-be dolly bird who buffs up the instruments of Todd's sordid trade with the oblivious cheeriness of someone scrubbing spuds. Paul Hegarty is a compellingly driven and underlyingly sad Sweeney, a man who starts off as a crusader against judicial hypocrisy but who, corrupted by obsession, becomes an indiscriminate killer. In an acute touch here, he offers his knife and his throat to Toby at the end. This is true tragedy: Sweeney's recognition that he has travelled way beyond redemption. An enriching detail that, like the production as a whole, offers a triumphantly new angle on a supreme piece of musical theatre.

Booking to 9 October (0870 060 6632)