José Cura breezes in from his rehearsal at the Royal Opera House looking rather like an off-duty nightclub bouncer. The dark-eyed Argentinian superstar, a former rugby player and body-builder, could have been tailor-made for the tenor lead in La Fanciulla del West, Puccini's take on the gold rush, for which he received rave reviews last week. His character, Johnson, aka Ramerrez, is an escaped Latin bandit, by turns a "goody" and a "baddy" in the best tradition of spaghetti westerns, but - in the best tradition of romantic opera - ultimately redeemed by love. Cura has run the gamut of "goody" and "baddy" in terms of critical opinion over the years, but it's his passion that carries him beyond that. His treacly, seductive, dangerous voice can knock you into submission in seconds.
Fanciulla gives him plenty of opportunity to let that voice shine. It's rarely performed, yet filled with vintage Puccini melody. "I first sang the role in a concert performance in 1992," Cura recounts, "so it's been growing inside for 13 years." He's particularly glad to be singing it at Covent Garden: "This production is a real classic," he says. "I remember watching it on video years ago and thinking, 'Hey, look at that, if only one day...' And suddenly you find you're in the middle of the set."
Cura's path to stardom took even him by surprise. His musical life had a difficult beginning; his native Argentina - where he was born with roots a quarter Spanish, a quarter Italian and half Lebanese - is a loaded subject. He hasn't been back for seven years. He adores Argentinian music, and dedicated the second CD he made for his own label, Cuibar Phono Video, to his country: "The Argentinian flag even appeared in the booklet," he says. "But the only country I couldn't sell the CD was Argentina. As the Bible says, no man is a prophet in his own land." His label, though, is doing fine: Cura is "in conversation" with a major label interested in taking Cuibar Phono Video under its wing.
If Cura had grown up somewhere else, he might never have found his voice. He began to sing through luck and necessity. "When I was about 12, I decided I wanted to be a musician," he says. "Argentina at that time was leaving military oppression and becoming a democratic country, but in the middle it wasn't so easy; you had to decide to do something reasonably useful. It was a big fight to make my parents understand I wanted to be a musician in a country where that was a hopeless decision. The purpose was to become a conductor and a composer. I had vocal coaching to complement the conducting, and one of the coaches said to me, 'Hey, you have to use this voice'. Later, a teacher told me, 'You don't have to be a singer, but you must learn how to sing, because that will make you a better conductor'. That was the best advice I received.
"It is always difficult to find opportunities to conduct or to get a premiere for your compositions - but in Argentina at that time, it was hopeless. Singing is a discipline where you can find some way to survive: in a choir, an opera chorus, or a musical comedy. I started to sing as a way of surviving. And, well, here I am. I survived pretty well." Once he had won Placido Domingo's Operalia competition in 1994, there was no turning back.
Is that rarest musical instrument - a glorious tenor voice - down to nature, or nurture, with hours of hard slog every day? Forget "hours", says Cura - even "years" would understate what it takes. "You cannot hurry up the processes of developing your voice," he says. "If you want to become a lawyer in two years, you can do it if you study hard, but singing is both intellectual and physical: the body has to have time to get used to what your brain understands first. And you can't stay home and work alone until you're 'mature'; you become mature by being out on stage, exchanging experiences with other singers and working with good conductors and directors.
"You can't expect wine to be more mature if you leave it longer inside the grape. You have to take it out and work on it. There are no miracles. I'm 42; I've been singing for 20 years and now - finally - I'm starting to feel that I'm kind of in charge. There's no way to do that only in the shower."
Italian and French opera has long been home to Cura, but will he ever sing Wagner? "I've been wondering too," he laughs. "The problem is the language. I can read and understand German, but I have not mastered it. To produce a believable character, one desperately needs the undertext, and there's no way to have that if you're reading phonetics. After so many years, people are used to a certain standard whenever I go on stage, so I feel uncomfortable with the idea that I would be performing knowing that I'm not giving what I'm supposed to give. When I go on stage, I feel secure in what I'm doing - you can agree with it or not, but you cannot say I'm not convinced or secure. If I give up on that security, I'd be giving up on the major secret that has made my career not only a success but a healthy success: I've never lost my nerve on stage. And I'm not intending to do so."
Cura, meanwhile, has found his way back to conducting; another happy accident, he says, that came about a few years ago when he conducted the Sinfonia Varsovia "as a joke", but found himself invited to become the orchestra's principal guest conductor - "much to the delight of my vocal detractors, who'd found the perfect excuse to say I'm a better conductor than a singer". Next season includes a stint at the Vienna State Opera, conducting Puccini's Madama Butterfly. He divides his time between singing and conducting "about 75 per cent to 25 - the perfect balance to prevent the singing from becoming a routine".
But thanks to his roots in conducting and composing, this most romantic of operatic tenors cites his greatest musical passion as something different: "Mozart said that, 'After J S Bach, each note we write can only be a commentary'. If you analyse Bach's music, you realise you can only try to be as good as you can be, without pretending to be more, because after that, what can anybody say? The experience that most touched my soul was conducting, years ago, the St Matthew Passion. One thing I regret is that I cannot sing Bach, because his works are far away from my type of voice."
Still, an artist such as Cura is never going to be pigeonholed. "The mood nowadays is to put people into specialised boxes - it's the most comfortable way of keeping them under control," he says, "but those who have things to do will jump out. I'm not alone; many people are trying to make society less cold in terms of specialisation. I don't see myself doing just one thing for the sake of avoiding being pointed at. I would be frustrated and I prefer to take the risks." He grins. "Altogether, it's not going too badly."
José Cura appears in 'La Fanciulla del West', Royal Opera House, London WC2 (020-7304 4000; www.royaloperahouse.org) to 1 OctoberReuse content