DANCE / Top hat, White Oak and tails: Judith Mackrell watches Mikhail Baryshnikov in a dazzling display of form

WHEN Mikhail Baryshnikov brought his White Oak Dance Project to London last year, his own dancing was remarkable for its reticence. It was true you couldn't tear your eyes from the spot where he was dancing. But the point of the company seemed to be not to celebrate Misha the star but, bravely, to present some of the less-performed greats and oddities of the modern dance repertoire.

In last weekend's brief season, though, Baryshnikov was back as the stellar focus of the programme. Dancing in Three Preludes, a solo choreographed by Mark Morris to Gershwin's piano music, he performed a loving fantasy on the sleek and debonair dancing of the Twenties and Thirties. Without a single literal tap step Morris's choreography distilled the loose-hipped grace, the deft syncopation, the dandy charm of Astaire and his era, while Baryshnikov himself sashayed and pirouetted with sublime elegance and wit.

Watching him was to witness a dancer at a rare watershed. At 45, Baryshnikov still looks startlingly fit. But added to the flukey instinct he's always had for making every move look effortlessly right, he now has the intelligence and acumen born of a long career. So lucid is his current dancing, so sure his musical response that it's like seeing choreography in a preternaturally ideal state.

Even more revelatory on Saturday night was the solo choreographed for Baryshnikov by Twyla Tharp. Pergolesi raced headlong through every dance language, every movement convention in the book and showed Baryshnikov as master of them all. Those with inside knowledge would have spotted the compressed story of his career running through the piece. Those without would still have marvelled at the ingenuity with which Tharp made every step a celebration of Baryshnikov's phenomenal range. In a single phrase he flipped from classical athletics to a casual post-modernist shrug, he embraced anguish and farce, turned angles into curves, shattered measured lyricism into loping jazz.

Such was the force of Baryshnikov's presence that the simplest crook of a wrist beamed from the stage - but he was equally capable of pushing back the stops and becoming one of the team. The rest of the programme was not about Misha, but about the choreography and the company - all of whom could more than hold their own. Hanya Holm's Jocose started out as a heady, uncomplicated whirl of jumps and turns that gradually peeled apart to reveal a range of oddball choreographic quirks - performed with sly good humour by the Project's uniformly excellent dancers.

Mark Morris's Mosaic and United, set to string quartets by Henry Cowell, was far less open-handed - a strange and lovely piece that showed Morris in an unusually oblique vein. Cowell's music unravelled lines of sound that seemed to hang suspended in space and in response Morris drew his dancers into powerful configurations in which they moved as if held by the form.

The spareness of the piece, the understated exoticism of its atmosphere was a far cry from the Royal Ballet's over-long triple bill of story ballets, with Balanchine's 1929 Prodigal Son, De Valois' 1937 Checkmate and Tetley's 1987 La Ronde.

The first, with its period mixture of Neo-Classicism and dark expressionism, is difficult for a modern company to dance, though on Friday night Irek Mukhamedov in the title role displayed the intensity necessary to give full weight to the choreography's rhetoric. Genesia Rosato, as the Siren, danced nowhere near dangerously enough, however. A far better pairing was Tetsuya Kumakawa and Darcey Bussell. He had all the feisty and hungry virtuosity to make a credible rebel, she all the grand physical allure to subdue him - you drew back in shock at the sadistic embrace where his head is crushed against her torso, pinioned by the steely angle of her bent leg.

La Ronde should be full of such shocks, given that it's based on Schnitzler's anatomisation of sex and syphilis in turn-of-the-century Vienna. Constructed as 10 pas de deux in which each character hands their partner on in a kind of erotic chain letter, it could be the vehicle for some seriously subversive dance. As it is, Tetley distinguishes so little between the characters and between their roles as seducer and seduced that the total effect is an anonymous blur of split-crotch lifts, suggestive arabesques and twirls - the women tearing off their frocks while the men, needless to say, remain fully dressed.

Final performances at the Royal Opera House tonight, tomorrow (071-240 1066).