DANCE / Glam slam: Judith Mackrell on near-perfection in the Royal Ballet's Ballet Imperial

Many of Balanchine's ballets are about hierarchy, with the dancers ranked in power and prestige like a mini court. But while, as in Ballet Imperial, the principals may be invested with a heightened glamour and status, Balanchine makes them work to keep their place. They not only have to dance with the grandeur and pride of privilege, they have to take bigger risks than everyone else and push harder against their mortal limits.

It's that lack of complacency which gives even Balanchine's most classically based ballets a peculiarly 20th- century twist and it's what makes Darcey Bussell their near-perfect exponent. Bussell always had the scale and strength of technique to make her a Balanchine dancer and she's now acquired the necessary command of stage. Yet, within the big plush phrases that she carves out of the music, you sense a constant tension of danger and defiance. There's something close to drastic in the way she angles her torso, flips direction or dives into a turn. And even when there's a blip in her control, it almost seems to intensify the drama of the performance.

It was good, on Wednesday night, to see Bussell dancing with her old partner Jonathan Cope - he matching her in size and attack but balancing her waywardness with an almost wistful romantic decorum. Less good was the sight of Benazir Hussein struggling with the second ballerina role. Cast from the shiny, leggy mould that's fast becoming an international ballet cliche, she has the looks but not yet the expertise for the role and she rushed through the choreography as if its ruthlessly precise demands were giving her the jitters. Sarah Wildor on the other hand, in one of the two soloist roles, was in command of every step. Though tiny for a Balanchine role, she danced with an instinct for elegance and grandeur, plus an absolute rightness of line that made the choreography glitter.

The two principal dancers in The Nutcracker - the Sugar Plum Fairy and her Prince - probably make the briefest dancing appearance in ballet, getting a bare 10 minutes to show off their stuff. But Tetsuya Kumakawa, making his debut on Saturday afternoon, is an old hand at hitting the stage with all guns firing and he managed to power through a solo of barrel jumps and pirouettes with enough energy to fuel a dance several times the length of this one.

Step for step he was matched in speed and chutzpah by Leanne Benjamin. Though, as a couple, the two didn't make enough of the choreography's singing line and its tugging undertow of nostalgia, they egged each other into a state of exhilarated daring that was gripping to watch - particularly in the sequence of fish dives when Benjamin flipped down and round Kumakawa's body like a wild leaping salmon.

'Ballet Imperial' is in repertory to 8 January at the Royal Opera House, Covent Garden, London, WC2. (Box office: 071-240 1066/1911)