Sadler's Wells Sampled, Sadler's Wells, London / <br/>Sylvia, Royal Opera House, London

From urban cool to Sylvan Glades

Sadler's Wells Sampled is a programme designed to tempt audiences: a little ballet, a little hip-hop, flamenco, contemporary dance, tango. Tickets are enticingly cheap. The evening shows are surrounded by a range of events, with classes, performances and interactive toys in the foyer. But it's the strength of the onstage programme that sells it.

It's a good mix of solo and company performances. For star quality, the prize goes to the French hip-hop dancer Salah. His Dream of Gluby presents a sweet cartoon character through squeaky beatbox vocals and an astonishing range of hip-hop dance styles. This is a virtuoso performance, presented with flirtatious, audience-winning charm.

Toddling forwards, Salah makes a squeaky-toy noise for each motion, exactly and wittily timed. His dancing is even more versatile. In a single phrase, he can go from robotic twitches to juicily flowing moves. At one point he demonstrates four elaborate phrases. You expect him to do them in sequence – but then he does them simultaneously, limbs snapping and rippling as his legs and torso shimmy.

Flamenco dancer María Pagés swoops into sculptural poses, torso arched or twisted. Turning in profile, she drives her way across the stage, heels drumming. As Pagés stamps, her fine musicians clap with her, in complex, brilliant rhythms.

In Yesterday, Yasmin Vardimon's company present a glimpse of a work that's still in progress. It starts with a dancer, precariously balanced on her partner's upturned feet, reaching out into the audience with a fishing rod. There's a camera on the end of the line, with shots of the audience projected onto the backdrop. The material sometimes loses focus, but it's all punchily performed.

Christopher Wheeldon's Prokofiev pas de deux is fluent and inventive but lacks individuality, though ballet dancers Alina Cojocaru and Nehemiah Kish are elegant. Boy Blue show an extract from their hip-hop Pied Piper, which is slick but overlong.

The Ballet Boyz, Michael Nunn and William Trevitt, make a good finale in a tango choreographed by Strictly Come Dancing's Craig Revel Horwood. Their timing and footwork have got sharper, and funnier.

Over at the Royal Opera House, Frederick Ashton's ballet Sylvia should be delightful nonsense, with its lovely Delibes score and frothy plot full of descending gods and forgotten vows of chastity. Yet it's taken a while for this production, lavishly reconstructed by the Royal Ballet in 2004, to find its feet. In this revival, the soufflé has finally risen.

Ashton created his frilly mythological tale in 1952, as a showcase for Margot Fonteyn. But Sylvia is more than a ballerina vehicle. The heroine dances solo after solo, displaying different sides of technique and personality. She's a huntress nymph who mocks love before falling for a shepherd. Abducted by hunters, she grieves and then dances seductively as part of an escape attempt. Finally, she puts on a tutu and gets married. The demanding choreography needs a star performance.

Sarah Lamb, making her debut, is fascinating casting. A dancer of magnificent technique and style, she has approached 19th-century classics with a reverence that becomes dull. Sylvia is a glimpse of how good Lamb could be in a tutu ballet, stepping past reverence into real dancing.

At first, she is a subdued huntress, but bursts into life once she sees the shepherd Aminta. Mocking him, Lamb puts colour and shading into her steps. You see Sylvia's changing emotions in her fluttering bourrées.

She has most fun in the second act. When she decides on mock-seduction, you can practically see the light bulb go on above her head. She's less happy in the last act, with its famously difficult pizzicato solo, but the dancing is always intelligent and alive.

Federico Bonelli, her Aminta, has the gift of innocence on stage. He bows to a statue of Eros with a simple reverence that makes this dotty story touching. His dancing is elegant in line and phrasing. His final solo has an extra dash and energy.

The Royal Ballet has now got the hang of Sylvia, which mixes fluffiness and tough technical demands. Sylvans, peasants, even dancing ceremonial goats take on tricky steps with bright attack.

'Sylvia' in rep to 31 March (020-7304 4000)