The youngest in a famous family, Jimmy Osmond is no runt of the litter. He has his share in the clan’s collective haul of 51 gold and platinum records, as well as his own set of solo gongs. He remains, rather astonishingly, the youngest UK singles chart-topper, courtesy of 1972’s Long-Haired Lover From Liverpool (he was not quite ten at the time, and had never been to Liverpool.) And he produces, too, not least on The Osmonds’ recent 50th anniversary world tour which went via Vegas, ran to a TV special, sold out two nights at Wembley (in an hour) and ended up at the O2 — or whatever it’s called this week.

“I’ve never stopped performing since I was a little kid. I do a minimum of 150 shows a year, and I have my own theatres as well. It’s what I do, and what I like to do.”

And now, fresh from his West End debut in Grease, Osmond is on the road as Billy Flynn in David Ian’s touring production of Chicago. Literally. I found him, by phone, somewhere between Liverpool, his “adoptive city”, and Stoke, where he had been doing a breakfast radio show. I began by asking the renownedly clean-living singer if playing the ultra-cynical Flynn, a defence lawyer who manipulates the media to generate public sympathy for murderers, wasn’t a bit of a reach?

“Well, have you seen the Richard Gere version? He doesn’t play the character as a sleazy lawyer, drinking, smoking, whatever. It’s not at all like that. When he played Flynn he was quite friendly. And I prefer the way he portrayed it, more so than others that I’ve seen. But everyone that’s in the role brings something different. And I’m 46 years old now, and I’ve had my share of experiences, so I’ll bring what I bring to the character.”

The show originated in a play by Maurine Dallas Watkins, drawn from her own classic reportage on a real Windy City murder trial. But with its raunchy numbers and Bob Fosse-alike choreography, I’m less-than convinced that West End (-style) audiences still view Chicago as a telling satire on our ludicrous obsession with celebrity. The opening lines of the UK tour press blurb scream: “MURDER GREED ADULTERY CORRUPTION — LET “CHICAGO” RAZZLE-DAZZLE YOU!” Isn’t it just sassy, sexy entertainment?

“I think it’s so smart, the way that it’s directed and produced, that you can get whatever you want out of it, y’know. You can go enjoy the glamour, you can go enjoy the music, you can go enjoy the whole storyline. The pacing is so fast, there aren’t these big dramatic pauses between lines — that’s why, no matter who comes to the theatre, they enjoy it, because it’s so quick.”

Playing alongside Osmond is Emma Barton (another veteran of the London production of Grease, but best known for her role as Honey Mitchell in EastEnders), as Roxie Hart, one of two alleged killers whom Flynn plays off against the justice system and each other.

“The cast is brilliant. Emma plays an amazing Roxie, and Twinnie [Lee Moore] an amazing Velma. They’re very particular in New York — where they own the lease — about how it’s played and the integrity of the show; but they were saying that this was one of the strongest touring troupes that they’d ever seen, which I think is really good for the cast. So that was a thrill, and the reviews have been good, which is always nice.”

I get the impression that Osmond is always, as a matter of professional courtesy, on cheery form; but he seems genuinely to be enjoying life on tour, and the playhouse routine.

“Oh yeah, it’s good. I grew up going to a different city every night to give concerts, but here I’m in each city a week, which is great. I actually get to check out the city, rather than just have it be a blur. Most of my life is a blur.”

Over the years he has toured the UK many times, and now spends a substantial chunk of his year in the country. “I have a special love for the UK: I’d live here full-time if I could. Lately, I practically do!”

He likes it so much, in fact, that he’s flying his family (just the immediate family, not the whole tribe) over to see Chicago, “to Oxford as a matter of fact”.

“We always make an effort to be together all the time: we’re like a little school of fish, wherever we’re going.”

Despite his numerous tours, though, this will be Osmond’s first performance in Oxford.

“I’ve been through it so many times. And I’ve been behind the scenes plenty of times, with different productions that have toured here. My wife wants to check out Oxford, and I love Oxford. Even as a kid I always wanted to go to college in Oxford. And never did.

“But you never know: there’s another generation coming up, with my kids — maybe they’ll go. That would be very cool. Then I could move in with them and go back to school! It’s never too late to learn something.”

lChicago runs at the New Theatre from April 27 to May 2. Tickets on 0844 8471585.