Hair, Gate Theatre, London

Nudity here is not rendered respectable by distance and discreet lighting. Before they plunge into their version of the famed nude scene, one of the company archly reminds her colleagues that the punters here aren't sitting in some vast 2,000-seat venue. The in-yer-face hedonistic frolic is followed by an episode where defenceless creatures cower in hoods and form human pyramids pointedly reminiscent of Abu Ghraib.

Kramer and gang are trying to pull Hair into the 21st century. I'm not sure how far this updating can be made to work, but there can be no doubt that the production has fantastic flair and a lovely, uncorrupted spirit. The main snag is that young men in the Sixties - including, presumably, the original cast - faced the draft. This threat does not hang over the NYU students whom we see here chilling out, after classes, with sex and drugs.

Charles Aitken has a terrific, luminously lost quality and gives a performance of transfixing sensitivity as the central character, Claude. There's a brilliant sequence where ,at his parents' home, Claude goes ape. But I could never quite believe that, for all the conflicting pressures on him, he would later volunteer to go to Iraq, where, a part of him supposedly believes, "people are creating, defending something".

When Michael Bogdanov revived the piece in 1993, the reviews were stroppy and dismissive, asking what possible relevance a musical that posits free love as the antidote to war could have in the age of Aids, and questioning the anti-Americanism that Bogdanov laid on thickly, with Death personified as a skeleton draped in the Stars and Stripes. Twelve years later, with the resurgence of American imperialism and the waging of another unpopular war, Hair seems to have found its moment again. There will surely be a life beyond the Gate Theatre for a talent-packed production that proves that this musical has a life beyond the Sixties.

To 8 October (020-7229 0706)