Arts: Dance: It's magnificent - but is it really a ballet?

BALLETT FRANKFURT SADLER'S WELLS, LONDON

A LOT of people have tickets for the British debut of William Forsythe's Ballett Frankfurt and I hope they find what they want. The Forsythe at the Sadler's Wells is not the post-classical choreographer made familiar by the Royal Ballet. This Forsythe is a post-post-classical adventurer whose journey from his ballet roots has gone so far it is often unrecognisable as ballet.

You can still catch glimpses of the spectacularly extreme classicism that first made Forsythe's name - although there are no pointe shoes here. But his own extraordinary dancers are more individual and versatile than the average ballet dancer.

They help him create choreography where phrases are broken down into small bumps and twists, transitions magnified and energy channelled into a fluid continuum. They perform pieces where conventional stage etiquette is exploded, so that dancers saunter on and off, sit in secret contemplation or stand about disparately. They think nothing of manoeuvring their own lighting equipment or performing in pools of almost total blackness.

The last of the three pieces, Quintett, seems the most lyrical and the most direct. On the surface it is a series of choreographic variations for five dancers, starting with a solo for Stephen Galloway. But actually the cast all exist in a state of imminent collapse. Their contours wobble and concertina; their legs buckle; their duets become struggles to regain vertically. Gavin Bryars' accompanying Jesus' Blood Never Failed Me Yet sets a quietly emotional mood, as does the knowledge that Forsythe made the piece as a message of hope again death. At the end a lone woman moves against a square of sky, and when she sinks backwards, a man steps out to push her back up.

Hypothetical Stream 2, made by communicating instructions via a stream of faxes, evokes an isolated human colony in a vast space, heads raised expectantly as if listening out for the melancholic trombone and intermittent foghorn. The performers operate individually, or else writhe in knotty clusters derived from drawings by Tiepolo. A joined-up trio, for example, seethes and tugs like a single organism, while a woman stands frozen in mid-gesture.

There is no narrative, although with Enemy in the Figure we might be watching the shreds of a nightmare, caught up in a swirl of darkness and light and the machine rhythms of Thom Willem's score. Figures run chaotically. A rope seems alive. And disturbing games of concealment and visibility play themselves out, with some dancers hidden behind a giant screen and a man erupting to scramble desperately up a wall. It seems an apocalyptic vision of the collapse of form.

The Sadler's Wells programme gives an opening taster of his kaleidoscopic means and imagination. Rumour says he might return with one of his composite full-evening works. It might be hell for some, but it's heaven for me.

To 28 Nov (0171-863 8000)