Mendes turns Dahl's 'Charlie' into a lavish feast of a musical

Chocs away! At last, Britain gets to see the much touted stage musical based on Roald Dahl's children's classic Charlie and the Chocolate Factory. Although there's been much talk of the technical challenges involved in adapting it to the stage, the real difficulty lies in preserving the story's humanity amid a welter of special effects.

Of course, this glitzy production will have to battle for universal applause with an earlier production of the author's Matilda, Gene Wilder's whimsical Willy Wonka in the 1971 film and Johnny Depp's turn in 2005 - not to mention the audience's memories of the book.

But acquiring the rights was a two-decade personal quest by director Sam Mendes. "I spent 25 years trying to get the rights for Charlie and the Chocolate Factory to do on stage," the 47-year-old said at the play's recent London premiere.

The success of his production lies in its reminder that, for all the razzle-dazzle of Mark Thompson's sets and costumes, Dahl's story is essentially a fable with a moral.

David Greig's script goes to pains to keep the narrative clear while shrewdly tweaking the original. It also builds up the character of Charlie's Grandpa Joe (played by the angularly funny Nigel Planer), who here is a bed-bound Billy Liar. Even Willy Wonka, the eccentric capitalist who seeks to monopolise the world's chocolate supply, is given a darker tone than in the book.

The show also depends on delayed gratification. Most of the first half is taken up with the story of Charlie's impoverished family, relieved by inserts of a garish TV spectacle showing the winners of the golden tickets. The only problem is that Marc Shaiman's score never achieves lift-off until Charlie himself becomes the lucky fifth recipient.

In what seems like a concession to the global market, the four other children on the tour are of mixed nationalities: the greedy Augustus Gloop is Bavarian; the spoilt Veruca Salt, defiantly English; the gum-chewing Violet Beauregarde, Californian; and the computer game-obsessed Mike Teavee, a product of American suburbia.