Off to New York to duet with Tony Bennett. When you have something like this to say, you ought to slip it in nonchalantly for maximum effect. As you can see, I couldn’t keep myself from blurting it out.

I pick him up from his apartment on the south of Central Park and we head off towards the Queens District, where he grew up. Going over East River, he gets talking about his great old friend and early champion, Frank Sinatra. This is as it should be, because we are on our way to the music and arts school that bears that singer’s name. Bennett has been heavily involved with the place since it opened in 2001, and his partner Susan is its assistant principal.

I’ve been rehearsing in my hotel down on West 58th, and wondering who I should be. There’s quite a list to choose from — Billy Joel, Elton John, Celine Dion, Sting and Paul McCartney. These are five of the 18 stars with whom the 80-year-old Bennett has chosen to duet for his latest album. As we speak it is already shooting up the US album charts, selling 200,000 copies in its first four days. In the end I settle for Stevie Wonder because the song he sings with Bennett is the very hummable 1967 standard For Once in my Life. Obviously no point in trying to sing like Wonder, who snakes all round a melody line and hits just about every note except the one you’re expecting. But Bennett’s rendition is wonderfully noble and dependable. I could easily work with that.

The reason I’m on this mission is that I’ve been instructed to ask him whether his type of singing really can be taught. With most interviews you are poised with your next question while the subject talks; with this one it is going to be a matter of coming in on the right note. The trouble is that no one seems to have told him that I am to be his pupil. And he hasn’t yet done the day’s vocal exercises which he says are essential to keep the voice in good order.

Walking next to such a legend, I am reminded that America elects a chunk of its royalty through the box office and the record store. People of all ages seem to bow as he passes. They don’t actually flex at the waist, but they don’t need to because of the respect and deference pouring from their expressions. This is one of the good guys. During one of his comebacks, in the late Eighties, he even became the first animated real-life character in The Simpsons. He returns to Queens two or three times a week, plays tennis with his old friend Mario Sirabella, a restaurateur. Sometimes he goes by his old home in Thirty Second Street, where he used to raise pigeons.

“I knew Thomas Wolfe,” he says. “I mean the one from the 1930s, who used to say ‘You can’t go home’, but I’ve found myself going home all the time.” Sure, he was a friend of Sinatra, and Dean Martin and Sammy Davies, and speaks lovingly of them all. But his name never seemed to feature in stories of drinking binges and unsavoury friends. And sure, he’s had some dark days, with two divorces and financial chaos, but here he still is, with a smile that has the effect of a radiator on a cold day. If ever there was an example of how to stay in the same place, artistically, and let the world come round to you again, it is Bennett, courted as in his heyday by the covers of the coolest magazines.

Up in a crowded classroom in the 500-student school, Tom Sandrin is driving a piano in a way that only American vocal music teachers can. The Broadway stars of tomorrow are giving it everything. In a rare lull I ask him if crooning can be taught and he says “But of course” and makes a go-ahead sign with his hand. Tony Bennett is standing next to me, and there are pictures of Sinatra everywhere. I kick off into the first line of the song: “For once in my life I have someone who needs me.” Luck has landed me on a note the piano recognises, and we carry on into the second line. Then Bennett comes in but he’s not singing, he’s just talking. “One thing you have to keep in mind is never push at all, just try and hit the centre of that note like you’d try and hit a bull’s-eye. And do those scales. You know, the first day a singer doesn’t do his scales, he knows it; the second day his musicians know it, and the third day his public knows it.”

I say I’ve been practising all morning in the hotel bathroom and, forgetting that bathroom is American for toilet, I can’t see why the kids think this is so funny.

“Someone I’ve needed so long.”

“Hold it there,” says Sandrin. “Try and let the rhythm move your breath, as well as moving the lyrics. You know, I grew up listening to Tony Bennett albums — I had no idea I’d be here years later.” Me neither. Then suddenly there’s a familiar sound on my right. It’s Tony Bennett’s voice, and it’s singing: “For once, unafraid, I can go where life leads me/ And somehow I know I’ll be strong.” And then I go:

“For once I can say this is mine, you can’t take it/ Long as I something something I can make it.”

And that’s it really. That’s the duet. I could go for the big top note at the climax of the tune, but I bottle it — such a mess if you miss — and feel myself shrinking back into the safer antiphonal mode of the interviewer. They’re like a high basket, aren’t they, those notes. You see them there and wonder how you’re going to make the height and still control the ball. “They are,” says Bennett, and then does precisely that, accurately and effortlessly. “It’s the breathing before each phrase,” he adds afterwards. “You have to make sure you have enough air for the next phrase.”

On my tape there’s a scratchy recording of all this, and I shan’t be sending it to Sony. As I listen to it I wince (at me). But there is something else in there — the sense, just the sense, of what it must be like to drive a Daimler when you are stuck with a Metro. That, and the realisation that these lyrics, like so many more of the classics, are deceptively brilliant. They can sound like poor light verse, but they rise into life, movingly and dramatically, with the infusion of such a breath as Bennett’s.

Explore Music

• CD Reviews

• Live Reviews

• Classical

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010