He not only managed to bridge the generation gap, he destroyed it, his effortlessly smooth delivery and timeless tunes connecting with an audience who had been raised on rock, yet he did it all without compromising his chic and unique style.
"I've always played to the whole audience, so I think the corporations are the ones that were shocked, not me," Bennett chuckles down the line, speaking from his apartment overlooking New York's Central Park.
"I knew just from performing so many times that if there were young people there, then they loved it. But there were standing ovations when we did the MTV album, and they were all teenagers, and that really reaffirmed that I was on the right track. It reminded me that I love the fact that I sing to the whole family, as opposed to singing to a certain demographic group."
Does he agree with Frank Sinatra's appraisal of rock 'n' roll as "that foul-smelling aphrodisiac"? "Well, it still is exactly that. I just regret that when rock 'n' roll came along, it seemed to make all the sharpest-schooled musicians and the truly great singers redundant overnight. I was in the Stage Delicatessen on Times Square 48 years ago talking to the wonderful singer, Jimmy Durante, who was having chicken soup. I was next to him, and I said – Mr Durante, what do you think of rock 'n' roll? And he said, 'They play three chords, and two of them are wrong'."
Since 1970's Tony Sings The Great Hits Of Today!, an album that saw his record company cajoling Bennett into performing contemporary songs by the likes of Jimmy Webb and The Beatles, he has steadfastly stuck to the music he grew up with. Indeed, Bennett, who has cut more than 100 albums in a career that began on 17 April, 1950, with his recording of Boulevard Of Broken Dreams, has spent several years putting together The Ultimate American Songbook, a collection of some of his most popular and iconic songs by the likes of Cole Porter, Irving Berlin, Duke Ellington and George and Ira Gershwin.
Although much of the material dates back to the early part of the last century, Bennett believes that each song is utterly timeless, mainly because people of all ages can still relate to them: "They were written in the Twenties, Thirties and Forties – way before my time – and that's when everything was optimistic, even though they were living in tough times. The songs never dated. They were all about quality, they have never been forgotten and they get better each time you listen to them.
"I mean, if you say 'Isn't it a lovely day to get caught in the rain'," he sings down the line in his instantly recognisable voice, "you never get tired of hearing that, and I never get tired of singing it either. It's like at the turn of the century in art when you had all the Impressionists… Monet, Gauguin and Van Gogh. Even though there's modern art now and everything seems to be abstract, when you look at a Monet painting, you have to say, 'My God, just look at how beautiful that is'. It's the same with music. It was a renaissance period in the United States that created the best popular songs that were ever written. Those songs are never going to die, and that's why I love them."
The son of a grocer and Italian-born immigrant, Anthony Dominick Benedetto was born on 3 August, 1926, in the Astoria section of Queens, New York. As a child, he nurtured the two passions that would stay with him throughout his life – painting and singing.
"My father died when I was very young, and my mother had to raise three children during the Depression. My mother was a seamstress, and she had to work for a penny a dress to put food on the table. I remember her coming home with bleeding fingers. In fact, I wanted to become an entertainer so I could buy her a home and stop her from working, and I was able to do that in her lifetime. In Italy, my father used to stand on top of a mountain and the whole valley would hear him sing, and that's why my brother and I decided to become singers. My brother sang opera, and he was much more talented than I was. He didn't continue singing, but I just had this passion to entertain people.
"I think I inherited my love of life and the love of staying together in the family from my parents. Everybody in our family would come over each weekend, they would make a circle around us and take out the guitars and then my brother, my sister and myself would entertain the family. They admired my painting and my singing, and they really gave me the passion to just sing and paint for the rest of my life."
As a teenager, he sang while waiting tables in New York and subsequently performed with military bands throughout his overseas army duty during the Second World War: "When I came out of the war, I joined the American Theatre Wing School, and they gave us the best teachers anyone could ever dream of. I was taught how to hold on to my voice by doing the scales of the Bel canto technique, which at 83 makes me sing just as well as I did when I was 50."
His big break came in 1949 when comedian Bob Hope discovered him singing with Pearl Bailey in Greenwich Village, a moment that would immediately change the course of his life: "After the show he came back to see me in my dressing room and said, 'Come on, kid, you're going to come to the Paramount to sing with me'. He also told me he didn't care for my stage name – Joe Bari. I told him my real name is Anthony Benedetto, and he just said, 'We'll call you Tony Bennett'."
Over the years, he has collaborated with many of the most important jazz musicians in history, from Bill Evans to Duke Ellington. Although many people perceive him to be a crooner, much like his heroes, Bing Crosby and Frank Sinatra (who continually cited him as the "best singer in the business"), what makes Tony Bennett truly unique in his field is the fact that, whatever material he works with, he has always been a jazz singer at heart.
"I am a jazz singer, and I'm not bragging when I say that," he explains. "I love jazz, because it's so honest and I'm moved by it. I even paint in a jazz fashion. It's all about spontaneity and first instincts. I was talking to the great Miriam Spier on 52nd Street – the great jazz street – and she said, 'Don't imitate other singers, just listen to jazz musicians and find out how they're phrasing'. I liked Art Tatum's piano playing, and Stan Getz had a great, wide, honeyed sound on the saxophone, so I tried to put those two together. By studying them, I developed my own style.
"I remember one time Count Basie said to me, 'Why change an apple?' That was a good lesson. You don't have to change if you're doing something good."
He speaks with the same warmth and honesty with which he sings, so it's hard to understand why Tony Bennett rarely agrees to being interviewed. The only subjects he appears to be slightly uncomfortable discussing are the brief period in the 1970s when he succumbed to a cocaine habit and the dark days when the Mafia leaned heavily on him, as they had done with many of his peers.
"In the Seventies, I was burning the candle at both ends, but it wasn't just me… everybody got ripped and we all hit a wall," he sighs. "It was terrible. I pulled out of it just in time, and I'm completely happy with life now. I learned my lesson… I learned that I thought I was doing great, and I wasn't. I did have some problems with organised crime and it was very intimidating, because they were trying to have a complete grasp on me, but then I just walked away from it. It wasn't any fun, let's put it that way."
With the passing of legends such as Sinatra and Ella Fitzgerald, Tony Bennett is the last in a line of interpreters of classic American song, yet unlike most singers of his vintage, he is still at the top of his game well into his eighties. As long as he is enjoying what he does and is still able to perform, Bennett sees no reason to stop.
"I get more of a thrill from performing now than ever before. I'm sold-out wherever I play in the world, and it's so gratifying to know that so many people are enjoying what I do. I sleep well at night because I know I made the audience feel great, and that makes me give that much more to them.
"People say I'm getting better as time goes on, and that's why I don't really feel like retiring," he beams with palpable pride. "I paint every day, and I still play tennis three times a week, so I'm in top shape right now. If I keep my health, I can get better, because I can just keep learning and learning. You know, life is a gift, and we're all born, we live and then we die, but the trip is such an adventure we should just cherish every moment that we're alive. It's a wonderful adventure, it really is."
Tony Bennett – The Ultimate American Songbook is released on Monday on Sony Music. Tony Bennett plays the Glasgow Royal Concert Hall on 4 July.