His concerts are sometimes schmaltzy spectacles where the audiences appear as entirely lost in the moment of absolute joy as the smiling man creating it all - the King of Waltz himself, André Rieu.
With a repertoire that includes Edelweiss, The Blue Danube and I Could Have Danced All Night, crowd-pleasers are his stock-in-trade. One night in New York, at a venue beloved of Frank Sinatra, he had the crowd singing along to My Way. Another night in Australia, he played the theme song to Neighbours. It is a style of classical music that, according to Donald Clarke in the Irish Times, makes "Richard Clayderman seem like Karlheinz Stockhausen".
That said, Rieu has an inner sadness that you'd never imagine from listening to his music or attending one of his instantly sold-out shows.
The biggest-selling classical musician in the world is talking proudly about how his father, Andries Antonie Rieu, was a conductor "in the classical sense with his face to the orchestra, while I have my face to the audience most of the time".
He adds that his father once dressed up the orchestra in period costumes when they were playing Mozart music.
"I remember that evening very well. I was a small boy. There were candles on the music stand. It was so romantic, really beautiful. I think that sort of theatre thing in my shows I inherited from my father. He had the soloist for that concert picked up in a Mozart carriage. So I got the theatre gift from my father."
It is all very upbeat fare, but then I casually ask what gift did his mother give him. There is a short pause followed by a bittersweet symphony dedicated, unhappily, to Alice Christina Maria Kleijntjens.
"That is a good question," he begins. "My mother and me were not so good together. She was a cold person. And I'm a very warm person. I have not so very good memories of my mother."
Did he reconcile with his mother before she died? "No, no…" he says, haltingly. "It wasn't [reconciled]. We had a very cold relationship. She did not believe very much in me. The moment I blossomed was the moment that I met my wife," André says of Marjorie Kochmann, whom he married in 1975. They have two sons, Marc and Pierre.
"She believed in me. She made possible what I am now. Without her, I would lie in the gutter, with a bottle of Irish whiskey."
Did his parents get to see their son become famous across the world?
"My father just saw the beginning and then he passed away," he says, "and my mother saw everything because she passed away last year."
And what did she say to him?
"She never said anything to me. She never said that she was proud of me. She never said, 'We made a mistake when you were young, not believing in you, because now see what you have achieved'. She never said that to me. She never spoke to me."
That must have been very hurtful?
"Yeah," he says. "It was very hard. It cost me several years in therapy to get loose of that terrible thing, because of course I would have liked to have had a lovely mother who believed in me, who loved me, but that was not the case."
You have turned out pretty well, André, I say.
"I worked very hard for it," he says. "I worked on it, to solve that. Perhaps it is my energy. I am not a person sitting down and crying, saying, 'Argggh!' I go forward. There are worse things. Some people don't have a mother at all. Or their mother or father beat them. There are worse things than happened to me."
The musical superstar and Marjorie live in Maastricht, Holland, in a 16th-century castle once owned by Charles de Batz-Castelmore d'Artagnan - who was killed at the siege of Maastricht in 1673 and inspired Alexandre Dumas's romping fictionalised swashbuckler in The Three Musketeers. Apropos of châteaus, Rieu's 2008 world stadium tour had an actual-size replica of Schönbrunn Palace, in Vienna, that left André in financial ruin to the not very classical tune of $36 million.
"That was a hard time of course because I was thinking too big," he says of his imperial error of judgment. "After that, I was bankrupt really. The bank said to me, go out and do concerts because that is the only way we get back our money. I promised Marjorie never to do that again. The palace is still there. It is in a warehouse."
He says he had never heard the music of The Beatles or The Rolling Stones until he met Marjorie in the early 1970s. "My education was very severe and very classical," says André, who played the violin from the age of five, and attended the Music Academy in Brussels.
Marjorie too was steeped in the classical music tradition, but "when I met her we listened to The Beatles and The Rolling Stones together."
Rieu would like to work with Bruce Springsteen one day. He is modest enough to admit, however: "I don't know if Bruce Springsteen even knows my name. He is a big example for me. I have great respect for him, his music. The energy he has on stage is fantastic."
Where does his own seemingly inexhaustible onstage energy come from? "I was born like that," says Rieu, who was born on October 1, 1949 in Maastricht. "Marjorie always says to me, 'You are four horses and I am pulling them back.' That's true. I can only run or sleep all my life."
Because of Covid-19, the grand master has had no choice but to slow down. "Because we were travelling the world giving 100 concerts a year with my 'second family', it is s**t, terrible," he says. "Sometimes I think, 'How should the end come? What would be the last concert? An accident or an illness? But nobody thought of this situation in the world," he says of the pandemic.
How does that affect his creativity? "It is still there. I'm a person who cannot sit still."
On March 14, he was in America "to do a concert when Trump said to the nation, 'Please don't go to concerts any more because it's dangerous'. We flew home immediately. And since then I'm baking cakes at home. I'm a cook but I have never baked so many cakes. The whole house smells nice. I don't eat them all but it gives me a lot of joy.
"Of course we have a lot of material from all the concerts to lift the world up. We make compilations for the cinema," he says referring to his latest release, André Rieu's Magical Maastricht - Together In Music. "I am a positive person. I am sure things are going to be good again and we can jump up on stage and play for the people. It is a great feeling that my audiences across the world are waiting for me."
What goes through his mind when he is conducting his orchestra in front of a giant audience?
"My brain is 100pc turning. I have a sort of radar with the audience. I can feel every second with the audience when they are with me. That's why I travel the world doing concerts, because the audience is really with me. I'm not playing for empty chairs. I'm playing for lovely, warm-hearted people. And that's why we are in a packed hall, because they want this warm feeling. I see everything. That is a gift I have. The people feel that I play for them - because I do."
"I have a lot of energy," he goes on, "and I use a lot of humour in life because I think humour is a fantastic tool to solve problems before they even come. Humour is a very good tool."
To test him, I throw a quote at him that he said almost 20 years ago: "I'm nothing more than an old, ugly man of 52 with an egg-shaped head which I try to hide under my long hair."
"I'm 70 now," he laughs. "And nothing has changed."
André Rieu's Magical Maastricht - Together In Music is in cinemas for two weeks only from September 18. Check out www.andreincinemas.com for participating cinemas
The evening of April 19, 1995 was literally a game-changer for André Rieu. He performed at half-time in the Champions League semi-final second leg between Ajax and Bayern Munich at the Olympic Stadium in Amsterdam.
It was more than a performance. It was a rallying call: 40,000 fans waved flags as Rieu played The Second Waltz by Shostakovich. Ajax were 3-1 up against the mighty Germans.
Then, as Ajax star Ronald de Boer said, "when we came back to the field, Rieu still had a swing in the stadium. And that helped. I think Jari Litmanen made it 4-1 within two minutes. The final blow."
Ajax went on to win 5-1 and get to the final in Vienna, where they beat AC Milan, with 18-year-old Patrick Kluivert (pictured) coming off the bench to score the winner.
"That performance at half-time in Amsterdam changed my career - and my life," Rieu says.
And if Ajax had lost to Bayern? "My life would have been totally different."
Ajax manager Louis van Gaal, Rieu says, "came to one of my concerts. He said he was very jealous of the way I coped with my orchestra. 'I am going to do this with my crew because it is so important to make a team of them.'"
Another hugely important performance for Rieu was at the Ground Zero site in New York four weeks after the September 11 attacks.
"I performed Lost Heroes for the fire-fighters. It was so emotional. Oh my God, it was terrible to see all the rubble."