Plácido Domingo: 'I've done nothing to deserve this voice' This passion would explain his bold decision to change his vocal range - after all, giving up opera completely would have been difficult for a man who says that his life is the stage. The baritone roles of Verdi - his favourite composer of opera (he wishes Beethoven had written many more operas than Fidelio; and says he's sorry that Brahms didn't write a single one) - helped him to make the change from tenor. I believe Verdi wrote his best music in the scenes when the father and daughter, or father and son, are singing together because unfortunately in his life he had two children and he lost both. Domingo, incidentally, has three sons. So I think you feel the drama and the feeling of his music in those scenes and I want to do these roles. His part in Giovanna d'Arco was such a role, and his chemistry with the Russian soprano Anna Netrebko lifted an already sumptuous performance. Born in Spain, Domingo was brought up by parents who performed zarzuela, the Spanish form of operetta. The family moved to Mexico when he was eight, and Plácido only began voice lessons after studying the piano and conducting. Before breaking through as an opera singer in his early twenties, he made money playing the piano in bars and taking small acting roles in television plays. Indeed, his operatic acting is frequently commented upon, and his performance in Otello, the role for which he is the most famous, was even praised by Laurence Olivier. "Opera is drama," Domingo has said. He quickly established himself as a tenor with an international reputation. By the time the world was awed by the first Three Tenors concert during World Cup Italia 1990, he had been on the scene for almost three decades: "Each of us had 25 years in the bag." Nonetheless, singing with Luciano Pavarotti and José Carreras enhanced Domingo's standing worldwide. They sang in 35 concerts together, a blend of impeccable pedigree and bonhomie. We had the best time. Was their any professional rivalry? It was healthy competition - it was like anything you can do, I can do better. In 1983, he declared he wouldn't go on singing beyond the age of 50 because there were other things he wanted to do. Later, he took up directorships at the Washington National Opera and the Los Angeles Opera, adding a coast-to-coast lifestyle to his air miles. He says he accepted them because he thought he would have to retire and so he would conduct instead. And here I am, almost 20 years later, and I'm still singing. Then, in 2009, after almost half a century as a tenor, he decided to take on a baritone role. Domingo intended to play the baritone part in Verdi's Simon Boccanegra when he felt ready to retire as a tenor and leave it at that. But Daniel Barenboim "pushed" him into it earlier than he had planned, in Berlin and at La Scala. And then everyone started to ask him to do it, and so he did - in London, New York, Madrid, Vienna. This led to an offer to do Rigoletto as a baritone in a live broadcast from Mantua: "Live television. Big danger, risk! I did it, and it worked. So then I said, Listen, I cannot sing the tenor roles the way I was doing it before - obviously at my age, it will be impossible - but I find my voice is there, and I can colour my voice to make it darker. I don't pretend to be a dramatic baritone, but I think the public is happy with what I'm doing and I think it's working. He says that he doesn't pretend to be the greatest baritone of all time but that he wants to touch the public. It's a privilege for me to make them happy. Domingo also credits his wife of 51 years with playing a key role in his performances. After his brief first marriage - begun when he was just 16 - Domingo wed fellow singer Marta Ornelas in August 1962. They studied together and went to live and sing in Israel for three years. They now have eight grandchildren. "My wife was a singer, a wonderful singer, soprano," says Domingo. But she gave up singing to bring up their boys and help him with his career. Much later she became a stage director. She has such a phenomenal culture for aesthetics. You see a rehearsal - you might see everything is fine. She immediately finds what is not working, what is working, and she applies that to me. She doesn't get in the way of the director but concentrates on what I should do aesthetically, and my performance starts to develop. While Domingo feels his country's economic pain - "I'm pro-EU, but I don't think it's working, I think it has become too big" - he does his own suffering on stage. He's a happy person in real life. It is fabulous to be able to live these different characters. One day, you are one character, then another day you are another. You suffer so much. I love to suffer on the stage. But if he purges himself on stage, he can still be restless after a performance. So yesterday, for instance, I couldn't sleep until about 4am. Because I was thinking about everything that had happened, and then when you think you can't sleep, you still think, you take the score, you see the things that you'd like to improve. So it is difficult. Unlike many in his profession, Domingo is no prima donna. Sir Antonio Pappano, music director of the Royal Opera House, has said: "For Domingo to cancel, he would have to have been on his death bed." So how does he manage to combine decency with stardom? It's because I believe things can finish tomorrow. You haven't done anything to deserve to have a voice, it's something that is given and could be taken away. There are some people who make everything difficult. They don't want to rehearse, they want this, want that, they complain about everything - and OK, I know that things can go wrong, but very, very rarely do I complain. Just how long Domingo will continue to sing is impossible to predict. I don't know if I will sing maybe one more week, maybe a month, maybe a year, maybe five. At least when he finally retires, there will still be the recordings. He's made more than 100 - not just complete operas but compilations and crossovers, too - won 12 Grammys and has just launched an album of 18 Verdi arias, his first as a baritone. Who will be the great tenor of the future? Oh, it is already Jonas Kaufmann. When the man who - if he remembers - likes to walk on to the stage left foot first, does step off it for the last time, he may have a little more time for a different audience. I have to do so much rehearsing that I very rarely sing for myself - even though some of my best performances are under the shower.