DANCE / Selected steps: Judith Mackrell celebrates an uninterrupted evening of Merce Cunningham movement

Watching one of Merce Cunningham's Events is a peculiarly chaste and restful experience for anyone willing to enjoy the liberation from conventional structure and from interval disruption. These performances don't feature separate works but are assembled out of bits and pieces of the repertoire, strung together into a continuous 100 minute show. The viewer - unpressured by the need to perceive the logic of individual works and undistracted by the intrusion of drinks and chat - is drawn into a strange, free-floating world of pure dance.

Each Event is tailored to its location - which in London has been The Queen Elizabeth Hall. Embellished only by coloured light, shared with four musicians who improvise on a bank of instruments, the stage becomes a functional arena for some of the most interesting dance in the world.

Because the material is potentially drawn from the whole repertoire, the variety of steps, shapes, patterns and rhythm is overwhelming. The evening opens with a long section of skittering flight where the dancers leap, twist, patter and dart on a bewildering and exhilarating diversity of counts. The open texture of that section contrasts with a later passage where these bird-like creatures stalk out their territory in stern lines, their limbs swiping the air in decisive curves.

As always Cunningham turns space into a magically fluid, magically charged element. At one moment the whole area is focused intently around a single duet - the dancers' bodies becoming tenderly infolding curves. Without any noticeable transition that image may then be enlarged by an orderly disposition of other bodies on stage, or it may be overwhelmed by a sudden swarm of activity. There were two glorious climaxes on Friday night, first when the stage was invaded by about 15 dancers stretching and ruffling like half wakened animals and later in a blithe hopping jig.

Most of Cunningham's dancers looked on effortlessly top form - precise but with a fearless, sometimes sensuous drama to their movement. Yet the quick centre of them all remained Cunningham, on Friday night dancing two solos. The most extraordinary of these began with him seated on a chair looking quizzically at his dancers. Left to himself he manoeuvred his way through a series of strange, out-of-kilter positions while radiating an atmosphere of deep repose. Then he broke into action and danced a solo involving such urgently vibrating hand movements that he seemed to be tuning into some high-frequency thought waves. The Event not only celebrated Cunningham the sorcerer-choreographer but also Cunningham the performer - enigma, seer and total showman.

From there to the Royal Ballet's current production of Swan Lake is about as large a leap as you can make, given the degree to which the latter's gracious classicism is cluttered with designer excess. On Thursday night though the company danced so well that they more than held their own against the surrounding wire and net. The enthusiasm beamed out by corps and soloists was underpinned by a gritty discipline and there were a couple of wild, show- stopping moments from Tetsuya Kumakawa in the Act 1 pas de trois. A tiny, compact demon, Kumakawa idled out of a furious string of pirouettes into a coolly perfect arabesque, and concluded each sequence of jumps with a cockily exact flourish.

The cast was led by Zoltan Solymosi (Seigfried) and Darcey Bussell (Odette/Odile) who between them sparked a very pleasing chemistry - pacing each other for speed and gutsiness. Solymosi looks increasingly relaxed as an actor and displaying more and more technical finesse. Bussell still has occasional problems controlling her long body and on Thursday got badly out of rhythm in the gruelling 32 fouettes. Yet she also uses her height for magisterial effect. The astonishingly slow unfolding of her leg in developpe can look unbearably vulnerable (Odette), or outrageously suggestive (Odile) and there are moments when her phrasing is so opulent, graceful and free that she seems to be dancing in some special, unregulated time and space.

Swan Lake is in rep at the ROH (071-240 1066)

(Photograph omitted)