A virtual reality that's larger than life

<i>Merce Cunningham </i>| Barbican, London <i>Thecla Schiphorst </i>| ICA, London

Imagine dance without plot, characters or symbolism, without sexuality or emotion, set to music that bears no relation to the dancers' movements. One might once have called it perverse, unlikely, even impossible - except that Merce Cunningham had done it. He began his grand aesthetic experiment in the US in the Fifties and, remarkably, at the age of 81, is pursuing it as keenly as ever. Last week his company brought his latest opus, BIPED, to London, courtesy of Dance Umbrella and the Barbican's BITE:00 season. And it showed the old radical still pushing at the outer limits of possibility - both practical and imaginative - to thrilling effect.

Imagine dance without plot, characters or symbolism, without sexuality or emotion, set to music that bears no relation to the dancers' movements. One might once have called it perverse, unlikely, even impossible - except that Merce Cunningham had done it. He began his grand aesthetic experiment in the US in the Fifties and, remarkably, at the age of 81, is pursuing it as keenly as ever. Last week his company brought his latest opus, BIPED, to London, courtesy of Dance Umbrella and the Barbican's BITE:00 season. And it showed the old radical still pushing at the outer limits of possibility - both practical and imaginative - to thrilling effect.

Cunningham's latest kick is digital technology. He's been using a computer as a choreographic tool for years now, helping him sequence movements that the body's logic wouldn't come up with on its own. A programme called LifeForms enables him to play with a 3-D droid on screen so that entire works can be perfected before he even enters the dance studio. The novelty of BIPED is that he brings this wizardry into the foreground. Designers Paul Kaiser and Shelley Eshkar have worked with so-called capture motion animation to allow these virtual bipeds to perform on a gauze screen alongside the company's 14 flesh-and-blood ones.

From the opening moments of Gavin Bryars's score you sense a change. Could my ears be deceiving me? We have tunes! Well, perhaps not full-blown melodies, but sustained stretches of tonal loveliness - lush, by the standards of most Cunningham-commissioned scores. The company dancers, however, seem unaffected by this luxury - accustomed as they are to squeaks and blips - and the five solos that unfold display all the arid detachment of MC's trademark style. It's like watching various species of insect manoeuvring around a patch of grass. Engrossing, but not involving.

The arrival of the digital figures prompts an audible gasp from the Barbican audience. Their luminous, more-than-lifesize silhouettes are lissom, beautiful, even awesome, suggesting the very qualities of soul that the live dancers deny. Their graceful, gravity-free dances are mesmerising, less when they perform feats impossible to their solid counterparts - such as dancing upside-down on a gymnast's bar - than when they assume human qualities. The single moment when two of them embrace I found absurdly touching.

As this long and complex piece progresses, the computer décor appears increasingly to merge with the live action. Or could it be the other way round, and the real dancers begin to respond to their virtual environment? The graphics morph into different forms - a series of cartwheeling shapes like spirolina; neon-coloured diagonal slashes like sleeting rain or falling willow leaves. You see, one's imagination runs riot. And who would have thought it at the start, with those blank-faced, sexless dancers? For me, that's one of Cunningham's achievements: to make us see abundant life by subtracting it from the human form and illuminating it elsewhere.

But the complexity of staging BIPED had clearly taken its toll. Gone was the clean co-ordination we know this company can produce. And this told even more in the brief companion piece given on Wednesday night: a re-run of Cunningham's 1968 marvel, RainForest. While it was fascinating to catch even a faded refraction of the subversive energy that fuelled this work back then (décor of silver helium-filled pillows by Andy Warhol, nude Lycra leotards personally ripped with a razor by Jasper Johns), thepiece cries out for context, andits 20 minutes seemed mean followed by an interval of another 20.

Another item that made me feel short-changed was Thecla Schiphorst's installation at the ICA. Bodymaps: Artifacts of Touch invited you into a darkened room in which was a table, covered in white velvet, on to which was projected a blurry video. This could in theory be activated by touch: by stroking, tapping, or generally getting friendly with the velvet surface. But Schiphorst clearly hadn't counted on the inhibition of rain-soaked Brits. Among my crowd there was definite resistance to stroking a semi-naked female image (people tended to touch the blank areas, it seemed more polite). And in any case the manner of touching didn't make any discernible difference to the progress of the images and sounds. It would have made a brilliant Candid Camera scam, though.