Dance Theatre of Harlem, Sadler's Wells, London

So what went wrong? On paper, Dance Theatre of Harlem's second programme should be superb.

So what went wrong? On paper, Dance Theatre of Harlem's second programme should be superb. It's an all-Balanchine bill, celebrating the centenary of the choreographer's birth. Apollo, The Prodigal Son and Agon are among the 20th century's greatest ballets. Harlem, a company with Balanchine roots, should know how to dance them. But for most of the evening, these dancers look lost.

Their first trouble is the music. Why dance this most musical choreographer to a taped soundtrack? There's an immediate loss of spontaneity, and it's much harder for the dancers to shape their roles musically. These recordings aren't that good, and they sound worse on the booming sound system at Sadler's Wells.

Then there's the question of technique. Balanchine extended and reinvented classicism. He brought in jazz steps, thrust hips, even turned-in legs, and made them part of the rigour of classical ballet. The classicism of Apollo is radiantly assured, even as the dancers walk on their heels or dip turned-in knees. It shouldn't be effortful.

The Harlem company danced Apollo for the first time this year. They're working very hard at the jazz qualities of this 1928 Stravinsky ballet, but they don't have the classical strength to hold it together.

Rasta Thomas is a strong, athletic dancer with a huge jump. Those powerful leg muscles don't necessarily help his Apollo. His legs and feet look heavy and unstretched. It's not a thoughtless performance; he's careful about contrasts of mood and direction. But he doesn't have the line or the phrasing for a young god.

Apollo isn't a success, but you can see the ballet struggling to get out. The Prodigal Son has evaporated completely. Duncan Cooper is a blank Prodigal. The explosive frustration of the early dances is lost in blandness. He goes through seduction, despair and repentance without really paying attention. Caroline Rocher's Siren is all complacency and fudged steps. Instead of swinging her shoulders, she shakes her elbows; when she should unfold a leg, she yanks it through the air, neither bent nor straight.

There's a glimmer of hope with Agon. The last Stravinsky-Balanchine collaboration, made in 1957, looks back to 17th-century court ballet and forwards to serialism and jazz. The dancing is uneven, but the ballet's shape survives.

The night's best and strangest dancing came from Alicia Graf in the pas de deux. Her physique is extraordinary: a small sleek head, long body, long limbs. She's smooth, very strong, and flows into extreme positions with the ease of pouring syrup. Agon is full of splits and high extensions, beautifully strange poses. Graf corkscrews herself into something even further, stretching a high attitude until her head seems to rest in her instep. But even the exaggerations come without a hint of strain.

To 10 April (0870 737 7737) then touring ( www.worldwidedanceuk.com)