Try as I might to dispel the cliché, half of me still expects Harry Connick Jr to be draped over a piano for our interview, veiled in Marlboro smoke and sipping bourbon. That’s not how it turns out, of course. It’s lunchtime, for a start, and smoky ivory-tinkling wouldn’t go down well in the cafeteria of Connick Jr’s sober London hotel.

Dressed in hoody, jeans and baseball cap, his stubbled jaw working purposefully on forkfuls of salade niçoise, the 40-year-old looks more like a veteran quarterback than a Grammy-winning jazz musician in the middle of a European tour. He is actually here with his actor’s hat on, for the release ofP. S. I Love You, in which he stars opposite Hilary Swank. The film is a lightweight but agreeable piece of rom-com tinsel in which Connick Jr plays a New York barman who benignly circles a grieving widow (Swank).

Seventeen years after being catapulted to fame after his movie debut in the Second World War film Memphis Belle, he is making a habit of starring in female-friendly fare. There has been a recurring role in that favourite of a million girlie nights in, Will & Grace, a stint on Broadway in a romantic musical, The Pajama Game, and in the pipe-line is another rom-com, Chilled in Miami, in which he will co-star with Renée Zellweger.

In fact, the man who was billed as the new Sinatra when he emerged as a musician in his late teens, and who followed the same double career path, admits to something that would have made Old Blue Eyes blanche: a feminine side. Instead of a Rat Pack, this father of three daughters is surrounded by an inner circle of women.

“I have a lot of great girlfriends,” Connick says, using the word as a woman would. “Hilary [Swank] has become a great girlfriend. There are about ten women who I would go out for dinner with, see a movie with. I like the company of women a lot, probably more than the company of men. Maybe it’s that in the formative years in my life I met my manager, who’s a woman; I met my wife. My sister’s a very strong woman. Or maybe it has something to do with losing my mom.”

Anita Connick died from ovarian cancer when Harry was 13, but he dismisses suggestions that it stiffened his ambition. “Nah, man, it just hurt like hell. It didn’t toughen me up at all. It screwed me up more than anything.”

His mother was New York Jewish, his father New Orleans Irish Catholic. “When my dad brought my mother to New Orleans to meet the family it was a big deal. Not that they were racist – they were just deeply rooted in their faith.” She was welcomed but “it made for an interesting childhood for me. They had very contrasting religious beliefs but never seemed to compete”.

Connick was left to decide which religion he wanted to follow; surrounded by Catholic friends and family members, he opted for his father’s faith, and was baptised at 14. He may have inherited his musical ability from his mother’s side of the family – his grandmother was “a singer of sorts” in Hungary, while his maternal uncle was a composer.

His bantering ease in front of crowds, meanwhile, may owe something to his parents’ professions: his mother was a Louisiana Supreme Court judge and his father, Joseph, was the New Orleans district attorney, displacing Jim Garrison, the governmental scourge played by Kevin Costner in JFK. “When I watched my dad on stage talking to an audience, he’s so natural; I’m sure it’s where that came from.”

Music has always been Connick Jr’s first love and, even after more than 20 screen appearances, he still looks far more comfortable in front of a piano than a camera. “I’ve done films that I’ve felt very comfortable on,” he insists. “I think it’s more about familiarity. The first few movies I did, I didn’t know the craft at all, whereas I’ve been on stage since I was 5 years old.”

He had started playing the piano at the age of 3, and was playing in jazz bands by the time he was 10, before studying as a teenager at the prestigious Manhattan School of Music in New York, where a Columbia Records executive persuaded him to sign for the label. He recorded his first, self-titled album of instrumental jazz standards at the age of 19, and added his languid vocals to the mix on the 1988 follow-up, 20. In 1989 he made his first contact with the film world when he released the soundtrack to When Harry Met Sally, which included a Sinatra anthem, It Had to Be You, that he made his own.

A key influence was his home town of New Orleans, whose unique opportunities had made music such a natural option. “I was a member of the musicians’ union, and I’d get a call saying, ‘Harry, are you free Thursday night, 6.30 to 9.30?’ I was 13 or 14! People like Ray Charles and Walter ‘Wolfman’ Washington would show up, really legendary people. The next night, you’d go and play a traditional jazz gig, and then the next night you’d play a classical recital.”

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