Sylvie Guillem, Sadler's Wells, London

Artistry and ageing inspire new works for the woman who thrills choreographers and audiences

Lean as a whip, subtle as a snake, there is nobody – and no body – on the dance stage as fascinating as Sylvie Guillem.

Now 46, she may have relinquished the classical roles that made her name, but her sideways step into contemporary work has seen no diminishing of her powers, not one jot.

For her latest venture – titled 6000 Miles Away in reference to quake-stricken Japan – she has commissioned work from veteran dance-smiths William Forsythe and Mats Ek, for whom she has been muse for 20 years. She has "a blue flame within her", is how Ek puts it, "in her movements, in her precision". Forsythe cites her intelligence on stage. The piece each makes for her is at once an act of homage and a clear-eyed disquisition on artistry and ageing.

Forsythe's Rearray, a duet for Guillem and Nicolas le Riche, a partner from her Paris Opera days, begins in typical Forsythe mode: house lights up, stage dark as a coal hole, eliciting a faint groan from a seasoned critic sitting behind me. Tricksy theatricals are soon forgotten, though, as a no-nonsense rigour takes hold, almost savage in its lack of frills.

Through a cobwebby veil of music by David Morrow, feathery strings and moans of horn slipping in and out of blacked silence, the pair work moves that intermittently hark back to their glory days. She flicks out an extended leg, swift as a lizard's tongue, or lifts an arm imperial in its curve. He beats his feet like hummingbird wings, or descends to one knee only to scuttle across the floor on both – a one-time prince brought to earth.

This is hardly your regular pas de deux designed for display of the female form. Workmanlike in T-shirt and jeans, Guillem risks total effacement in the gloom, though the liveness of her torso, her miraculous control as she whips or decelerates through turns, seems to confer heightened powers of seeing. This piece is hard work, though, and the first-night applause was muted.

Just as well, then, that Mats Ek opted to exploit Guillem's comic talents, creating in Bye a quirky solo that envisages for her a slightly batty old age, with the help of a video portal from which a dog, a family and sometimes her own self peer out at her with curiosity. Recalling the popular poem that begins "When I am an old woman/ I shall wear purple ...", Guillem dons a jumble-sale skirt and frumpy blouse. But even these cannot mask her articulacy as she zones in and out of reminiscence, cartoon stick-body giving way to lithe effusions of girlishness, headstands included. All this is set to the sublime last movement of Beet-hoven's final piano sonata that some will shudder to hear used this way, but Ek just about gets away with it.

Less successful is Guillem's bid to clear herself some recovery time by drafting in two stars from Nederlands Dans Theater to deliver a slick duet by Jiri Kylian as the sandwich filler. They were superb, and sexy too, but it was the middle-aged Parisienne with the peculiar half-way haircut that everyone had come to see.

Returns to Sadler's Wells 22-25 Sep.

Next Week:

Jenny Gilbert sees the rarely staged Romeo and Juliet of Frederick Ashton

Dance Choice

It's an awful long trip and they don't make it often, so don't miss Royal New Zealand Ballet's short London visit, the first under starry new director Ethan Stiefel. A triple bill includes Bandillero, choreographed and designed by Javier de Frutos and set to the charged music of Chinese virtuoso percussionist Yim Hok-Man. At the Barbican, Thu, Fri & Sat.