‘Lose that padding!” snaps the producer of the Corny Collins TV talent show. Reluctantly the latest in a long line of would-be Elvises pulls a thick pair of socks out of his trousers. But the scorn directed at the unfortunate lad is as nothing compared with the vitriolic reception accorded to Tracy Turnblad when she arrives for her audition.

For Tracy is, to put it bluntly, fat— very fat. The year is 1962, and Tracy has decided that winning a talent show is her way into show business. Thus begins the storyline of Scott Wittman and Marc Shaiman’s musical Hairspray.

Tracy’s showbiz dream is immediately supported by her dad Wilbur, played by long-time Family Fortunes host Les Dennis.

“It started the same way for me,” Les explained when we met up backstage. “I did Opportunity Knocks in 1971, having started in the club world. I’ve got a lot of time for talent shows — as long as you’re prepared to then learn your craft, and use it as a platform. Certainly in the show it’s all about Tracy’s dream to go on a talent show. But she has bigger dreams than that.

I think the Corny Collins Show is based on a real show of around the same time that John Waters [writer/director of the film Hairspray, on which the stage musical is based] used to watch as a kid in Baltimore.”

Seeing the show at a packed matinee, it came over as a vibrant explosion of 1960s-style music and colour.

But the show carries darker, moral messages too, although it never preaches at you.

“It’s set at a time of segregation,” Les continued. “Tracy goes onto this Corny Collins Show with the support of her dad, but less support from mum Edna to begin with.

“Edna says, ‘they don’t put women our size on television except to be laughed at’. Tracy discovers that there is segregation within the show — there’s ‘negro day’ once a month, as opposed to ‘white day’ every day.

“She’s very much a pioneer, and she wants the integration of the kids on the show. It’s a great moral for kids today to come along and see that the world was a much darker, and different place only 50 years ago.”

Mum Edna is played by three different actors, who alternate the role as Hairspray tours across the country. But they have one thing in common: they’re all men. In Milton Keynes and Oxford, Edna will be played by the experienced Brian Conley.

Brian describes his varied career as “working just under the radar”. That means, he told me, paparazzi photographers have camped out on his doorstep only once — when he was offered a role in EastEnders. But this is the first time he’s played a woman.

“There’s a lot more to it than playing, say, a panto dame: that was drummed into me in the early days of rehearsing. Edna is a strong woman, and a character who grows as the show goes on. She starts quite dowdy, but becomes this wonderful, glamorous peacock. But there’s still no denying that it’s actually a man underneath.

“When Les and I kiss as husband and wife, the comedy really comes out of the fact that the audience knows it’s really two men kissing.

“There’s lots of comedy built into the situation — confusion on the phone when someone thinks they’re talking to the father when they’re talking to the mother, for instance. It’s very useful having a strong baritone voice, I can sing right down there into my boots.”

Hairspray tours to Milton Keynes Theatre from September 21 to October 9 and the New Theatre, Oxford, from October 12 to 20 (0844 847 1585 or newtheatreoxford.org.uk).