Merce Cunningham

Barbican, EC2

The venerable high priest of modern dance arrived in town last week, and what a humbling experience it was. With his 80th birthday fast approaching, shows no sign of easing up, let alone closing the book on his life-long disquisition into making art with human bodies. He was in London with his company (who never travel without him) for a run of performances at the Barbican Theatre - a highlight not only of the Dance Umbrella festival, but also, conveniently, of the Barbican's "Inventing America" year.

And invent is what Cunningham does, with the zeal of a man half his age. His own body may be halt and lame (arthritis now forbids the limited cameos he performed as curtain calls until only a couple of years ago), but the mind gallops on. And he still takes risks. The sort of risks that make theatre managers blanch.

On paper, the programme was standard fare: three works, one old, two new. In practice, the older work, one of the choreographer's legendary "Events", was a pick 'n' mix of past repertoire - some of it dated back to the 1960s - a kind of retrospective collage. Straightforward enough, you might think, but for one extraordinary fact.

Until the eleventh hour, the dancers do not know what material will make up this particular event. Nor do they know which parts they will be required to perform. The question of repertoire is decided by the choreographer on the afternoon of the performance; the question of casting is decided by a flip of a coin just before curtain up. Why does he do it? "It makes it more fun," he says.

It makes it more fun for us too. It's quite possible to watch a complete programme of Cunningham dance without being aware of this mindboggling test of memory and brinkmanship. But when you do know, it's intriguing to watch the dancers' reactions as the work pans out on stage. Even in the opening piece, Windows (1995), secret smiles passed between them at various points in the music.

You see, they hadn't heard it before. It was improvised on the night: great somnolent washes of electronic sound punctuated by crystalline tinklings and scrapings; lugubrious blasts of thick, black noise suggesting echoes of the natural world, pre-history. The smudgy backdrop and leotards by John Cage (no mistake: the composer also did visuals) are the colours of mud and rock, like the cave paintings of Lascaux without the pictures.

Although the subject of any Cunningham dance is never overt (he claims there are no meanings, you make your own), his work is in fact swarming with ideas and allusions. You simply need to empty your mind, Zen-like, and soak up the images one by one. Here, a raised-palm motif like the antlers of rutting stag; there, a precarious high-legged balance on one foot, held for a stalactite eternity. Bodies herd and cluster, forming tight circles of febrile, wriggling activity, then disperse to the winds once more. The dance doesn't develop; rather, it unspools. And there are moments when this sense of seamless continuity is almost panic-making. It could go on forever! Yet even at its most static, the combined strangeness and technical perfection of each individual movement makes it ravishing to watch.

The Barbican Event also offered the chance to revisit a Cunningham classic, Winterbranch. At its premiere in 1964, this work was seen as highly provoking. In Germany, audiences thought it was about the Holocaust; in Tokyo, they said it was about the atom bomb; in Sweden, race riots. Cunningham himself claimed simply that he had made a piece involved with falls, with bodies falling.

And that's how it looked last week, set to a new, improvised score. At one point - when some smoochy Latin dance tunes struck up - the dancers erupted in wide grins as their feet continued to pace out complex rhythmic patterns which were as miraculously in-step with each other as they were crazily out-of-step with the music. It was an exhilarating justification of Cunningham's belief that out of chance procedures can emerge art, and art that's different every time.

Perhaps it was last-minute gambling that delayed the final work of the evening. At any rate, it amounted to theatrical suicide to extend a 20-minute interval to almost an hour. But the delighted cheer that greeted the dancers' costumes proved all was not lost. In Scenario (1997), Cunningham made an unprecedented nod to high fashion by giving carte blanche to Rei Kawakubo, founder of the Tokyo fashion house Comme des Garcons.

Under banks of white fluorescent light, the dancers appeared in dazzling deckchair stripes and tablecloth checks, stretched tight over padded protuberances in the most unlikely places. Pigeon chests, lop-sided hips and hump backs struggled against the odds to keep up with the choreography's athletic and sculptural demands.

The effect was funny (principally) and, for the first 10 minutes, fascinating. The design element kept up the momentum with swift changes of colour in the lumpy skinsuits: to blistering red, then to malignant black. But, for the first time in a long evening, Cunningham's questing spirit seriously outran mine. That old panic set in. If there's no beginning and no middle, there's no end to this. Help. But then the lights went out. Thank God. still has a sense of humour. And the grand old man can still be an enfant terrible.