TOMMY Steele is not your typical 78 year-old.

When we meet in a Glasgow hotel, Britain’s most successful song and dance man is wearing trackie bottoms and a t-shirt that could have been bought in H&M.

Still touring - set to star in The Glenn Miller Story - his hair is still blond and curly, if a little thinner than it was when he was still Tommy Hicks from Bermondsey.

Tommy Steele even sounds young, talking in an excited luvvly-jubbly south London accent as he praises the PR team’s oatcookies.

“I feel fantastic,” he says, relaxing back in his chair, hands behind heads like a teenager watching a movie.

“My mum used to say I had the cheekbones to look young for ages. But the thing that really keeps you young is doing something you do.”

And avoiding ill-health? “I’ve been lucky, mate. All my ill health happened before I was eleven and I was ill for four years.”

Tommy reveals he developed porphyria, the neuropathic illness which affects the stomach and drove King George 111 mad.

“The war had been over three or four years, and I was trapped in hospital bed. It was only when these red spots exploding on my ankles the docs realised I had the King’s Disease. When I learned of the madness I panicked - and so did my mum.”

Young Tommy was treated successfully, although he later developed meningitis and cardiomyopathy. But did the madness the doctor predicted eventually emerge?

“Not really,” he says, smiling. “Although you have to be mad to go into showbiz.”

The performer became mad for showbiz as a young boy when his parents took him to the Paladium. “I was disappointed because I wasn’t a child star like Mickey Rooney. I didn’t think you could be English and be a star.

“I got on the Bermondsey bus and forgot about the dream.”

Until the 16 year-old Tommy Hicks joined the Merchant Navy. The teenager became chums with a sailor who taught him the three chords required to play every Country and Western song ever written.

When he watched Buddy Holly perform, Tommy learned to play rock n’roll. By the time the 18 year-old came back to London, the sexless tea-chest-and-moothie music, skiffle was all the rage.

But when Tommy Hicks walked into the 2i’s Coffee bar in Soho, took out his guitar and played Blue Suede Shoes, London was never the same again.

The following week, in October 1956, it was Tommy Steele who walked into Decca Records and made Caveman, reaching No 13 in the hit parade.

“I wasn’t looking for the success, it just came to me,” he says, grinning.

Come on, Tommy. The showbiz dream was always there. The Paladium. The guitar. The desire/nerve needed to play live in Soho?

“It’s a good point you make,” he says, grinning. “And you’re half right. But it wasn’t just about singing and playing. I needed an audience.

“When I played guitar and sang on the ship I loved to see the sailors faces light up. That was showbiz for me.”

Ah, showbiz. Long associated with thieves and opportunists. Indeed, the early days of pop was very much about managers preying on young talent, sexually and commercially. Was he a victim?

“To be honest, I’ve never been privvy to that.”

Just six days after the chart success, Steele was thrown onto the variety circuit after (he played the infamous Glasgow Empire) and a week later theatre producer Harold Fielding offered the chance to star in musical theatre.

“Oh yeh!” he says. “I didn’t know my a***from my elbow but I was having such a wonderful time. It was lovely.”

He adds, in serious voice; “There was never a plan. And there isn’t a plan now. You can call it luck or happenstance.”

Tommy didn’t care about being cool. “I’d play anything if it entertained,” he admits. And he did, courting the variety fans, the grans and mums and recording cheesy efforts such as Little White Bull.

Broadway beckoned, then Hollywood, to star in the likes of Finian’s Rainbow with Astaire. But was his blond head turned? Did he dabble in drugs? Did he buy an E-Type jag and hop around with Playboy bunnies?

“There weren’t groupies in those days. Mine were called Teenagers and the worst they would do is shout through my mum’s letter box. And I never took the drugs or drink, not because I was holier than thou but because I was getting all my kicks on stage.”

Steele bought his parents a house in 1957 and he was still living at home with his mum in 1960 until he married wife Ann. (They have a daughter, Emma).

Not only did he not trash hotels, sometimes he didn’t even sleep in them. When appearing in Liverpool in panto, he says he hired a caravan and slept in a field, away from the attentions of the Teenagers.

His boy-next-doorness seems absolutely genuine. But did he ever suffer from self-doubt, given it all happened so fast?

“It doesn’t go as deep as that,” he says, rather honestly. “And what I realised early on is that stars such as Gene Kelly and Fred Astaire were always working on their own work, trying to improve.”

Tommy Steele is still our Gene Kelly. And despite the fact he’s forty years too old for the role, he’s about to become Glen Miller on stage. Yes, he loves the music, but you suspect even if Steele were beaten on the head repeatedly with Miller’s trombone he’d still go out there and perform.

“I think I would,” he says, smiling. “I never want to give it up. It keeps me young.”

• The Glenn Miller Story, the King’s Theatre Glasgow, September 15-19.