Hairspray eminently deserves the four Olivier awards that accompany the Evening Standard Best Musical statuette on its mantelpiece. The show's combination of wryly upbeat songs, exuberant Sixties kitsch and a primary-coloured message of tolerance remains potent, its energy - even on a weekday matinée - undimmed.

Leanne Jones is every inch a star - in circumference and height - as the plus-size heroine Tracy Turnblad, even if Michael Ball is dragging out his dragged-up laughs as Tracy's mother.

Most impressive, though, is the way a sustained blast of Hairspray has brought the Shaftesbury Theatre back to life.

This always seemed one of the more hapless of London's 40 major playhouses. Originally opened in 1911 as the New Prince's, it was the last theatre built on Shaftesbury Avenue but was stranded at the northern end, in the area once known as St Giles's, a notorious former slum that never quite shook off its reputation for seediness.

Although the theatre enjoyed success in the Twenties with Gilbert and Sullivan seasons, and found a post-war role as a home for musicals, the rot set in in 1973, when part of the roof fell in, bringing to an end the record-breaking run of 1,998 performances by the nude, counter-culture singalong Hair.

After that, the Shaftesbury vied with the Piccadilly and the Playhouse for the title of London's unluckiest theatre - venues that, for reasons of geography or unfortunate programming became graveyards for shows, to which audiences could not be enticed.

Toyah Willcox once told me about the miserable experience of playing the place in her Eighties punk days, when it was so cold she could see the hostile audience's frosty breath. When we spoke she was about to return to the Shaftesbury in Calamity Jane, a show that duly joined the long line of musicals that, before and since, have keeled over and died there - Napoleon, Lautrec, Bat Boy, Thoroughly Modern Millie, Daddy Cool.

For a long time I thought the Shaftesbury should be bought for the nation and used to house the Theatre Museum's collection. Now Hairspray has rejuvenated it, and warmed up the local business and restaurants of St Giles's in advance of a major redevelopment of the area. I'm glad I was wrong.

• Booking to 4 April 2009 (020 7379 5399, www.hairspraythemusical.co.uk).