Saturday Night Fever, Apollo, Victoria, London

They've no respect for the so-called 50th birthday of rock'n'roll down at the theatres of Victoria.

They've no respect for the so-called 50th birthday of rock'n'roll down at the theatres of Victoria. At the Palace, they're still putting the Rod Stewart musical Tonight's the Night through the mill, and now, at the Apollo, Saturday Night Fever returns to the West End to stomp all over the mainstream fusion of black urban dance music and gay club culture that was disco.

It's easy to forget that the 1977 movie wasn't a musical at all, in that the characters don't sing. Based on a story by the rock journalist Nik Cohn, with a soundtrack by The Bee Gees, it's a gritty, well-constructed matrix of social mobility. Tony Manero (the John Travolta character) and his partner, Stephanie (originally Karen Lynn Gorney), seek transcendence through dance; his parents, through their elder son's position in the priesthood; the priest, through forsaking his calling; and Tony's tragic pal Bobby C, through giving up being the gang schmuck.

The boldest move of this production is its retention of the movie's bleak denouement, resulting in an ending even more downbeat than in that famous unhappy-ending show Sweet Charity. Not that any emotional depths are mined here, with a quick sprint through the angsty bits and several encores tacked on. The audience, in the main, have come to dance and blow a fuse on the whoop-o-meter, after all.

Unfortunately, the whole thing is more old-school Saturday-night telly than fever, with the choreographer, Arlene Phillips (who also directs), marshalling the chorus into a dance troupe and calling to mind those Seaside Special variety shows. Worst of all are Nigel Wright's orchestrations of the spry tunes of the brothers Gibb, which sound like some plodding homage to the Seventies theme-tune maestro Ronnie Hazelhurst.

The infectious and funky guitar figure that opens "Stayin' Alive" seems to be rendered by Bert Weedon in oven gloves. "Tragedy", a Bee Gees hit post-dating the movie but press-ganged into this version to illustrate a subplot (badly), shows Alex Jessop's dorky Bobby C in fine voice, but fares badly as a song when de-energised and used as a show tune.

Shaun Williamson steals the curtain-call for his Monty the DJ, a kind of disco-Everyman character whose wardrobe makes Huggy Bear look as though he shops at Austin Reed. He plays the audience like a banjo, and even gamely goes for falsetto in "Disco Inferno". Stephane Anelli, as Tony, gives little sense of the character's pent-up confusion, but he moves well, as does Zoe Ebsworth, who easily outdoes the clod-hopping Gorney in the movie. The Popstars winner Kym Marsh certainly won't be taking the accent prize with her Annette, caught as she is somewhere between New York and New Malden, and is also the least of the voices on show.

The exuberance of the cast is unquestionable. And they all look great in David Shields's costumes and on his set. But as a disco inferno, this mother never quite catches light.

Booking to 2 April 2005 (0870 161 1977)