"Socialism is about beauty," writes Barbara Castle. Against the discord of the 1984-85 miners' strike, writer Lee Hall conceived the ugly-duckling story of Billy Elliot, the miner's son who discovers ballet and, thereby, finds self-expression and beauty. In Billy Elliot the hit film (2000), directed by Stephen Daldry, you can see Billy, very affectingly, discovering self-expression; but ballet as beauty did not quite emerge. In Billy Elliot the Musical, again scripted by Hall and directed by Daldry, it does.

At one point, amid a chaotic ballet class, Billy (beautifully played on press night by 12-year-old Liam Mower) unwinds from a clumsy multiple pirouette into a sustained attitude derrière effacé- the most marvellous single moment in a new musical for decades. The image, childish but statuesque, says so much: beauty; ballet; the ability of the human to be become the ideal: a multi-dimensionality that is theatrically more real even than the strike, and strangely more serious.