André Rieu is sitting in the garden of his castle in Maastricht, in the Netherlands. With his long flowing locks he looks like a 61-year-old rock star. He is in fact the king of the waltz, the high priest of the violin. He is like a magician on stage, commanding such emotional performances from his orchestra that he had people waltzing in the aisles of London's O2 Arena last year.
The 2009 tour with his Johann Strauss Orchestra outsold any other male artist in the world. In all he has sold over 25 million albums.
Rieu is a flamboyant character, who is surprised by little. But even he was a little shocked when a celebrity fan called him to ask him if he would like to record his waltz. That fan turned out to be Sir Anthony Hopkins. "When my office called me and said there's a man on the phone and he says he's composed a waltz and he wants you to play it because he's a fan, I did not expect it to be Anthony Hopkins. I have these calls almost every week, but him, can you imagine? I thought it was incredible. He wrote this waltz nearly 50 years ago.
"He and his wife were both in front of the television watching one of my shows when he told her that his dream was to be playing music. I met him and it was like a love story. I helped him fulfil his dream and he liked me openly, everything I do, without criticism, without condition."
Sir Anthony Hopkins uses almost the exact same phrase about Rieu. "He is unconditional. André is a good counsellor, very generous and has a great sense of humour. I'd love to work with him again.
"My wife Stella encouraged me some years ago when we first got married to go back to music. 'Just compose,' she said, so I did. It is true that I wanted to be a musician long before I became an actor. Music was my first love. But times were different in those days. My father had to work very hard. We didn't have the opportunity to go to college or anything like that.
"When I was a kid I was fascinated by Vaughan Williams, Elgar and Russian composers. I didn't consciously imitate them but I was inspired by them. I had been composing for years, and this particular waltz [And the Waltz Goes On, which is also the name of Rieu's new album] I wrote in the green room of the Playhouse Theatre, Liverpool in 1964. I would go in early before anyone else and play honky tonk piano. I would get a tune in my head and write it down. I scored it for a complete orchestra."
The waltz remained untouched for nearly five decades until the moment he gathered his courage. "I phoned André. I didn't know him at the time, but I sent it to him. I'd always admired André. He's a superb musician, a terrific showman and a wonderful violinist. I've seen his concerts a number of times."
It was a brave move for the actor. He was 72 at the time. Having enjoyed decades as one of Britain's most established stars, he now wanted to start a new career.
Today Rieu is wearing an Hermès silk scarf that Hopkins gave him. "When we first played Anthony's waltz with the orchestra, I sent it to his iPad and he phoned me immediately. He said, 'I'm sitting here in tears,' and that was only the first draft. When I first heard his voice, that soft, nice, loving voice, I thought, this is incredible. Since then we have texted each other almost every day."
It was a few months after Hopkins first heard his waltz that he travelled to Maastricht to see it being played by the full orchestra. Hopkins describes the moment when he came out of the lift of his hotel and saw Rieu for the very first time, as if he were meeting a long-lost friend. "The doors opened and there he was," he says with wonder. "That night they played my waltz." Hopkins was moved to tears.
And the Waltz Goes On will be performed by Rieu on television for the first time on Strictly Come Dancing this week, and it is sure to be a very moving experience. "We really clicked together," ponders Rieu. "I'm very emotional. I dare to put my hand in the fire. I'm never afraid. And I don't think I'm offending Anthony when I speak, but he has told me that he has difficulty expressing his feelings and the music helped him."
The rhythm, the beat, the sometimes sad violins of the waltz are strewn with emotion. When I meet Hopkins, I ask him if he feels able to express himself best through his music, his acting or his painting. "Music, definitely," he replies, without missing a beat.