You can hardly count the ways in which Swan Lake and Sleeping Beauty have been reinvented. Few, however, have begun as radically as Edouard Lock's Amjad, with an entire reworking of Tchaikovsky's music. Gavin Bryars' score (written for piano quartet) is based on themes from the two 19th-century classics, but these have been merged into an utterly new sound world, with familiar melodies sliding into eerie dissonance. The effect is a disconcerting slippage between the known and the unknown, but it is also weirdly true to Tchaikovsky.
For Lock, it provides a haunting base from which to rethink the original Petipa-Ivanov choreography. What fascinates him is the Romantic licence embodied within the two ballets, as their heroes and heroines undergo intense emotional, sexual, even physical transformation. The sparest of stage designs - including images of crimson petals and virginal white sheets - marks the symbolic terrain, while the choreography delivers snapshots of deconstructed action. Ferocious, bewildered encounters between a man and a wild bird-woman are juxtaposed with scenes of courtly partying; a celebratory marriage duet becomes a hopeless dream for a chorus of tragic mourners; a prince finds himself transformed into an exquisite swan, dancing on pointe.
In one section, the music fades to the sound of a scratchy record while the dancers appear strangely disembodied - as if they have been dispatched to an afterlife for ballet characters. At over 100 minutes long, Amjad doesn't always hold together. At times the material turns repetitive, and some of its effects feel like meretricious tricks. But the essence of Lock's language is extraordinary, classical steps wired to extremes of speed and expression. And the focused conviction with which both dancers and musicians perform make this a true homage to its classical sources.
· Until Saturday. Box office: 0844 412 4300. Then touring until February 16.
