First Night: Hairspray, Shaftesbury Theatre, London

I don't know about yours, but my beehive had capsized with excitement even before the curtain had even gone up at the West End opening night of this Broadway musical version of Hairspray. Despite, I might add, furious back-combing and strenuous action with an aerosol in the gents to keep it erect. Normally, I go for the kind of windswept look that would count as a "hairdo violation" at the heroine's Baltimore High School. But I thought a bit of effort barnet-wise was appropriate for a musical that comes boasting eight Tony Awards. Was the show worth it?

Yes, yes and again yes. The piece takes us back to the early Sixties and a world before mass-obesity and worries about the ozone-layer had had time to make a chubby teenager with a spray-can begin to look like a dubious role model. So was this an innocent time in the Land of the Free? Not for blacks, it wasn't. Homing in on the Corny Collins television show, where teenagers try out trendy new dances, Hairspray exposes the segregation that relegated black kids to one "Negro Day" a month with Corny – or rather does until our portly 16-year-old heroine, Tracy Turnblad (an adorably starry-eyed and idealistic Leanne Jones) proves that she can not only out-Mash-Potato all the slim richer white kids but put an end to discrimination, too.

Powered by elating Sixties dance routines that are so infectious they will have to install compulsory seat-belts to prevent the audience from storming the stage, Jack O'Brien's production lays out perfectly the deal this show makes with the punters. It's a deliciously droll double-bluff: a giddy, high-spirited spoof of a youthful protest piece that, with the lightest of touches, manages to be the real thing at the same time.

As a fan of the original 1988 John Waters' film that starred Divine, the mountainous, no-holds-barred drag act, I had worried that the material would lose too much of its conscious comic tackiness when converted into a Broadway musical, despite the arch wit of the book, score and lyrics.

Michael Ball in the Divine role seemed about as excitingly blasphemous a piece of casting as, say, hiring Michael Crawford to play Leigh Bowery.

In fact, the fat-suited Ball, who is appreciably better than John Travolta in the recently released movie version of the show, gives one of the warmest, funniest and most oddly touching performances in a musical that I have ever seen. When Edna is a housebound slattern, he resembles Nero in the wake of some disastrous hormone injection; when Edna is spiffed up and learns to appreciate the worth of her girth, he has a weird look of A S Byatt. Yet with wondrously supple and amusing timing, he packs in an extraordinary range of tones – from moments when he gruffly acknowledges his maleness to sequences where he suggests a poignant shy delicacy and undimmed wonder in this woman who can't leave the house because she's ashamed of her bulk.

Hairspray knocks spots off Grease where the college kids are about as ethnically diverse as the Ku Klux Klan. Here, there are some great roles for black artistes, particularly Motormouth Maybelle, the R&B disc jockey who sings up a storm in Johnnie Fiori's knockout portrayal. And because it is about more than show business and contrives to be airy and fresh as well as knowing, it leaves The Producers looking a bit thin on top.