WILLIAM FORSYTHE is one of the most sophisticated intelligences working in dance today, exercising parts of the brain most other dance-makers fail to reach. After a messy run-in with Frankfurt politicians he will soon be leaving his post as artistic director of Ballett Frankfurt. This renders Ballett Frankfurt’s appearance this week as part of the Dance Umbrella festival something of an historic occasion.

The classically trained Forsythe is eminently capable of making pure dance pieces, but there are no safe bets with him. His taut, off-kilter style has stretched classical vocabulary to its limits. He continues to experiment with the ways that dance is presented, even at the expense of dance itself.

Forsythe is particularly savvy in his use of film and text, theatrical tools which are the bedrock of Kammer/Kammer. The piece begins in a spirit of jokily Post-Modern chaos. Dancers mill about a stage that resembles a TV studio or film set. Antony Rizzi, cast in a speaking role, is ingratiatingly keyed up. This might almost be a comedy revue.

Forget pointe shoes. The ensemble surrounding Rizzi is either in socks or barefoot. The pointiest things on view are the heels of Dana Caspersen’s caramel-coloured knee-high boots. Looking smart in a retro-chic suit and little black hat, Caspersen is the piece’s other lead.

Kammer/Kammer draws upon two texts pinned on homosexual desire.

The poet/scholar Anne Carson’s Irony is not enough: Essay on my life as Catherine Deneuve (2nd Draft) posits the French film star as a university professor consumed by unfulfilled longing for a female student. This is the magnificent Caspersen’s territory. Playing the narrator in Douglas A. Martin’s autobigraphical Outline of my lover, Rizzi muses with equal but more comic frustration on the emotional dissatisfactions of being the lover of a rock star.

In Kammer/Kammer their stories of desire, love and loss cunningly intertwine, thanks to a brilliant use of live video projected on to large plasma screens above and around the stage. Beautifully lit and edited, the multi-layered performance is packed with gorgeous, ironic images and role play. Classical references in text and score (Sappho and Socrates, Bach and Busoni) abound.

There is, in a conventional sense, little dance on view. Forsythe places eruptions of quickly-sculpted, fractured movement in shadows or “behind the scenes” of the mobile walls with which the space is reconfigured. Dancers tussle and slam off of bare mattresses. Not enough to satisfy anyone seeking straightforward dancing.

Yet those with open minds may be intrigued and transported. Kammer/Kammer doesn’t quite sustain its First Act magic. The shorter second half is loud and, perhaps inevitably given the material, dramatically overheated.

Hysteria and aesthetics are unhappy bedfellows. But this manipulation of film, speech and kinetics creates a mood both dense and evanescent.

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