When La Sylphide was first performed in 1832, its supernatural heroine, doomed hero and chorus of fairies in white dresses defined a certain iconography for ballet. In Britain, however, the work never attained popular classic status - at least not until now. Johan Kobborg, who grew up with the ballet in Denmark, has staged it for the Royal, and the mix of pure intelligence and pure enchantment driving his production should guarantee it a whole new audience.
Kobborg's Sylphide is rooted in the version staged by August Bournonville in 1836. It is profoundly traditional - yet it has the effect of rinsing clean the material and transforming the dancers. For instance, the men can only be described as blithe. It's not just that they're all dancing in kilts (although that counts for a lot); it's the fact that Kobborg and his assistant, Sorella Englund, have coaxed from them such radiant beats, finessed footwork and cruising jetés that all of them - from Ivan Putrov, as a flashing, moody James, to the little boys at the back - dance like bonny princes.
Kobborg's casting instincts are as astute as his coaching. There are some relative unknowns in the cast, with Iohna Loots a heartbreaking, eager Effie and José Martin a staunch but witty Gurn. But two of the performances are indisputably stellar. One, predictably, is from Alina Cojocaru, whose Sylph is so fast, so musical and so delicate that when she claps her hands, it's like the beat of a hummingbird's wings. She shows us exactly how deadly a heroine this Sylph is: captivating, capricious, but with the moral sense of a one-year-old. Just as mesmerising is Sorella Englund's Madge. In Englund's ravaged, railing portrait of the wicked witch we see a creature eaten alive by bitterness, not only revelling in her powers of destruction but haunted by them.
This production is a huge achievement for Kobborg, yet he deserves almost as much praise for his performance in Flemming Flindt's The Lesson. This enthrallingly nasty little tale - Noël Streatfeild rewritten by Hitchcock - has Kobborg playing a psychopathic ballet master, who, in twisted complicity with his pianist (Zenaida Yanowsky), murders his little pupils.
Kobborg and Yanowsky are impeccable, capturing within the caricatured grotesqueness of the choreography a history of thwarted power and sexuality. But it's a shame that Roberta Marquez as their victim seems to be dancing a different ballet. She is bold and pouty, playing for laughs, while the qualities that make this ballet really dark - her queasy, precocious sexuality - are barely hinted at.
· In rep until November 9. Box office: 020 7304 4000.
