Guaranteed to have you on the edge of your seat

DANCE

Are You sitting comfortably? Then William Forsythe will see about that. Complacency in plush seats is a red rag to a modernist like him. Here is the American choreographer's strategy for priming a ballet audience to a proper state of readiness. One, start the show prematurely (and hear them curse, as they struggle crouching to their places). Two, omit to dim the house-lights and then set off the interval bell. Three, give them a blast of glorious music - say, Bach's Chaconne for solo violin - then snatch it away as if the system's on the blink. So how are we doing? Teeth clenched? Nerves ragged? Good, then he'll begin.

Forsythe's Steptext is on its third outing with the Royal Ballet, but grows no less alarming with age. The front-of-house hi-jinx seem to work every time, leaving the audience with a bruised receptiveness to all the ideas on stage. This is ballet at its most risky, most brutal, most political, delivering a telling critique of the sexual dilemmas of our time by subverting familiar classic dance manners, turning male chivalry and feminine dependency on their heads. But Steptext is more than clever polemic. It has a lethal, thrilling beauty.

One woman (Deborah Bull, in a red-for-danger swimsuit) is courted by three men (Adam Cooper as the favourite, Peter Abegglen and William Trevitt as his rivals). She appears to collude in their athletic manhandling, swinging her extremities into ever-more-violent angles. An arabesque becomes a brow-on-kneecap slash mark, a backward fall skews into a torpedo dive, a resisted tug sends the ballerina skidding the width of the stage. Only trust and skill lie between Bull and a broken spine. Yet a semaphore of brandished fists says the lady's not for wooing. This formidable creature partners only when and whom she pleases. Passions have their place - under her thumb.

It is odd to reflect that this riveting 11-year-old work came into the company's repertory only as a peace offering in a crisis. Eighteen months ago, Forsythe pulled out of a major Royal Ballet commission, claiming that the dancers could not cope with his collaborative methods. But on the evidence of Steptext, the resulting damage should be consigned to history. William Forsythe's jagged edge is what this company patently needs to carve a niche in the next century.

The pressure might be lifted from Ashley Page, a senior Royal Ballet dancer who at present is in danger of spreading his choreographic talent too thinly. Since his huge success two years ago with Fearful Symmetries, Page appears to have inherited the mantle, if not the official title, of resident dancer-maker, and never a season goes by without one of his fast, edgy, classically based pieces. His craft is not in question, but inspiration has been patchy - never more so than in Two-Part Invention, the work premiered on Tuesday.

Page's initial miscalculation was to choose another piece of thrumming American post-minimalism as orchestral score. Robert Moran's 32 Cryptograms for Derek Jarman sounds like a steal from John Adams's Fearful Symmetries (only rather less catchy), and the first Part of Page's dance invention does nothing to dispel the sense of deja vu/deja entendu. The new piece hinges on a series of rather obvious contrasts: pop v classical, youth v experience, earthbound v airborne. More intriguingly, live movement is set up against shadowy filmed images of the same dance material, projected life-size on a cinema screen behind the dancers' heads, as if ghosting them in a curious time-warp. Perhaps we're meant to feel we've seen this all before.

Moran's clean and linear score is served by nine young unknowns from the corps de ballet, leaping and spinning like flowing paper streamers in the wind, their unmannered innocence underlined by feet freed from the tyranny of point shoes. This segues into Prokofiev's grandiose Fifth Piano Concerto, danced by a senior league who are spiky and imperious in their points and formal tutus. It's all very easy on the eye - too easy, though designer Peter Mumford's neon tubes and gorgeous jewel-coloured light projections jazz things up a little. But Page's ballet painfully lacks formal substance. It's fine to champion the language of classical dance - it's neither dead nor dying. But language is no earthly use without something worth the saying.

Triple bill continues at the ROH, WC2 (0171 304 4000), 4, 7, 14 & 20 Dec.