George Balanchine may have had a notoriously feckless record as a husband, but he choreographed some of the most sexually grown-up ballets in the repertory. In his Stravinsky Violin Concerto the dancers are, as always, the medium for his beautiful and musical pattern-making; yet their bodies are charged with such a dangerous, sensuous energy that there is another mesmerising subtext going on. When Darcey Bussell is lifted across the stage - her legs taut, her head back and her throat lushly bared - she looks like a woman in the aftermath of some appalling erotic triumph. When Leanne Benjamin snaps her limbs around her partner she moves with the instinctive aplomb of a preying mantis.
The women are magnificent, and the men court them with a febrile power of their own. Edward Watson is a flickering limber devil, while Johan Kobborg veers unnervingly from cockiness to self-abasement as he sinks to his knees before Benjamin and nuzzles mutely at her neck. It used to be argued that the Royal were much too well-behaved to dance Balanchine - but this season opener wickedly proves otherwise.
There is much less going on between the dancers in Glen Tetley's Voluntaries, beyond a mission to survive the choreography's exhausting demands. It starts with gaudily thrilling effects, as women are swung high in the air, their bodies arched violently backwards, and strings of turning steps explode like scattershot across the stage. But the pace never slackens, and after 30 minutes the ballet comes close to being a relentless, vacuous marathon.
On Thursday, however, it was redeemed by an extraordinary cast, led by Alina Cojocaru and Sarah Lamb, whose recklessly articulated dancing gave Voluntaries an aura of grandeur. It was made irresistible by the performance of Poulenc's Organ Concerto from the pit. Rarely does the Opera House music director conduct for the ballet, and Antonio Pappano's presence underlined how much it misses out. If the sound was eerie and huge for Poulenc, it was ecstatic for the Janacek, which accompanied the last work of the evening.
Sinfonietta is Jiri Kylian at his most swirling and folksy, but the music was played with such singing definition that the choreography took on a whole new clarity. In the final trumpet fanfare, as the dancers were lifted on waves of golden, full-throated sound, they and the musicians seemed to be sharing a single breath, a single heartbeat.
· In rep until October 16. Box office: 020-7304 4000.
