YOU may not know opera, but you know La Traviata. It's the one with the consumptive courtesan who is persuaded by her lover's father to give him up for the sake of his family's honour. Guess what? She dies at the end. You're bound to have heard Verdi's sublime duets if you've ever strayed onto Classic FM while twiddling the radio dial and might have felt a twitch of recognition if you've seen Baz Luhrmann's cinema spectacle, Moulin Rouge. At least on the big screen, wafer-thin Nicole Kidman, with her alabaster skin, could believably be dying of tuberculosis. Far too often on stage, audience disbelief collapses under the weight of the fat lady who sings her final aria slumping into a chair while one of her many chins wobbles unconvincingly.

La Traviata can be lazy programming by an opera company hoping for guaranteed bums on seats, La Traviata can be lazy programming by an opera company hoping for guaranteed bums on seats, from stalls to circle. It can be the epitome of every dumbed-down, cliché-ridden, endlessly revived production that ever gave opera a bad name. It's the opera David McVicar swore he would never direct. So what is he doing back in his home town, lording over rehearsals in the Theatre Royal, adding the final touches to a brand new production for Scottish Opera?

Born in Glasgow in 1966, McVicar studied at the RSAMD, before launching a career that has blazed through the world's great operas and opera stages - La Boheme, Carmen and Giulio Cesare at Glyndebourne; The Magic Flute, Faust and Rigoletto at Covent Garden; The Turn Of The Screw and Macbeth at the Mariinsky in St Petersburg; Don Giovanni, Manon, Il Trovatore and Billy Budd at venues as far-flung as San Francisco, Chicago, Salzburg and The Met in New York. But never, until now, Verdi's love story set in the 1840s.

"I've always hated La Traviata," says McVicar with trademark frankness. "I thought it was one of the stupidest operas in the world. I just hated the way it was traditionally presented, like when the curtain sails up and this woman seems to be living in the Palace of f***ing Versailles with all of the chorus poncing around in tiaras. It makes absolutely no sense because people have forgotten this is the story of the Parisian demi-monde; this is not the story of a consumptive countess."

Thankfully McVicar has, well, not recanted his theories exactly, but found more depth in Verdi's writing through his total immersion in the work for this Scottish Opera production. The key seems to have lain in rejecting any inherited notions of how La Traviata should be staged and going back for inspiration to the novel on which the opera is based - La Dame Aux Camelias by Alexandre Dumas the younger, who founded his fiction on a financially and emotionally doomed real-life affair with Alphonsine Plessis, a courtesan who went on to marry a count and who died when she was just 23.

"When I read the novel, I was absolutely fascinated by the intimate tone of it," McVicar explains when we meet in a cafe across the road from the theatre where rehearsals are taking place. "Because Scottish Opera is a small company that works in intimate theatres, you can make that a great strength and really find that quality of humanity - and just get away from the trappings of the piece."

McVicar comes with a reputation. Previous interviewers have found him fearsome, crotchety, difficult, diva-ish. Today, he is none of these. At first he seems wary of questions, tying me down again and again over the precise thrust of an argument or the meaning of individual words I throw at him. Perhaps some guardedness is to be expected, even from someone who is openly gay and has talked at length on earlier occasions about being diagnosed as HIV-positive seven years ago. But, then again, such attention to detail is his driving force; it's an important component of his directing style, in terms of his reading of the music, the performances he draws from the cast and the consideration that is paid to costume and design.

So when I mention that Violetta, the courtesan in the opera, attends balls, I am quickly corrected. "They were not balls. They're parties in apartments at 4.30 in the morning. She's not in society. She can't go to big lavish balls. The most that she can exist in society is when she rides in the Bois de Boulogne in the afternoon and goes to the theatre in the evening. And if she goes to the theatre, she's working."

When I suggest that certain productions have overplayed her angelic, self-sacrificing nature, turning her into a tart with a heart, I'm slapped down again. "But she's not a tart. She's a courtesan. It's a very different thing. You have to be someone to get through her front door. Her dying is part of that horrible 19th-century way that the audience in Verdi's time could sympathise with her because, when she asks to repent her past, she starts spouting sentiments which wouldn't be amiss coming out of the mouth of Julie Andrews."

When I try to push for a connection between the director and the female character, wondering if McVicar brings anything personal to this interpretation of the role (both suffered through an uneasy childhood but ended up in a glitzier stratum of society) I'm still, it seems, on shaky ground.

"Are you fishing?" he asks, before laughing. "I don't live in a glitzy world. I've got a nice wee house in Islington that I share with my boyfriend and my dogs, and we try to get there as much as we can, and nothing gives me greater pleasure than cooking Sunday lunch. It's not glitzy."

However, when we get back to talking about the character of Violetta, placing her in modern terms, it's not me who takes the conversation off at a tangent from the precise matter at hand.

MCVICAR says: "Violetta would have been the queen of London celebrity hangout Soho House. That's much closer to what she was doing. Our tragic diva, Amy Winehouse, is much closer to what Violetta was doing. The terrible thing about Amy is that she's got everything but she's throwing it all away. She's living so fast and probably has a death wish and doesn't expect to be around for very long. That's much closer to Violetta."

Ah, but surely Violetta behaves the way she does because she knows, somewhere inside, that tuberculosis will kill her in the end? "I think Amy knows what's going to kill her," McVicar adds. "I think Amy absolutely knows every time she takes heroin, what's going to kill her. I don't think she can stop herself; I think she's a destructive personality."

It clearly takes a very special singer to pull off McVicar's plans for Violetta, and the director believes he has found her in young Italian soprano Carmen Giannattasio. Already a veteran of several productions under the baton of Ricardo Muti at La Scala in Milan, Giannattasio last appeared in Scotland at the Edinburgh International Festival in 2006, as Elena in a concert performance of Rossini's La Donna Del Lago. McVicar has nothing but praise for her.

"I've seen La Traviata about eight times and I've never been moved before. But Carmen moves me. She presents a very tough, incredibly sad characterisation. She's such a visceral, honest actress. You don't have to fight through period conventions to understand the heart and soul of what she's going through. The vocal line is written to be sung with great intelligence and lots of dramatic colour. Carmen has a very dark sound, a heavy sound, a penetrating sound. She can invest a great deal of emotion in her singing, and that's really important."

Getting someone like Giannattasio on board - destined for stardom but still at an early stage in her career - is something that can perhaps only happen when a director with McVicar's pulling power comes to a company with the modest means of Scottish Opera. He is quite insistent he hasn't returned to Glasgow to prove a point to anyone from his past or to treat his home company as a charity case or even to repay Scottish Opera for early breaks (his previous contributions to their repertoire - 1999's Der Rosenkavelier and 2000's Madame Butterfly - came when he had already earned the reputation as the "enfant terrible" of British opera). So where does his loyalty to the company spring from?

"I just think I would be very ashamed of being a Scottish person if there wasn't a full-time opera company in my home country," he replies after a long pause. "It's a shame it's an art form that often turns into a sort of civic function and then gets deeply embroiled with governmental decisions because it's such an expensive thing to get on.

"I was really touched when I read somewhere that when Sir Alexander Gibson was trying to create the company in the 1960s, he said he wanted to lay the treasures of opera at the feet of the Scottish people'. That's all he wanted to do. He didn't have to devote his life to creating this company. He had a very successful career as a conductor and he made a real choice that he wanted to make this art form live on Scottish soil. I suppose that's why I've come back, because I believe in the same ethos. I think having all kinds of arts is a sign of civilisation, whether or not we're living in a civilised country."

The life of an opera director, McVicar admits, is a nomadic one. He has lived in London for 15 years and "certainly wouldn't call myself a Glaswegian except by birth". But for all his travelling and the fact his diary is often filled five years ahead (at the back of his mind today is a production of Berlioz's The Trojans due at Covent Garden in 2012), this can also be a very closed world, particularly when it comes to the critics who write for London-based national newspapers and magazines. McVicar expects the worst from them - not necessarily because his La Traviata has the audacity of being north of Hadrian's Wall, but because of his involvement.

He says: "Will they be patronising? I'm sure they will be for this. I'm thoroughly expecting it. Because I'm so goddamn ubiquitous these days, all the London boys and girls are sick of me because they see my work all the time. But it's not my fault companies keep reviving the shows. I'm just too successful, and you're not allowed to be successful - that's a Scottish thing, but it's a British thing as well.

"Of course some of the London reviewers don't know what to think if they're seeing, say, Shostakovich's Lady Macbeth Of Mtsensk. Maybe they don't know Lady Macbeth Of Mtsensk, so they find a colleague who does. I once heard he names a famous critic from a well-known newspaper going to he names an equally famous critic from an equally well-known newspaper going, Are we enjoying?' Sometimes they really don't know."

The curtain is about to fall on our time together today. McVicar finishes the dregs of a glass of wine and looks across to the stage door of the Theatre Royal, where he has to return to iron out a few final details before La Traviata premieres on Thursday. But for a moment, his mind flits from the centre of Glasgow to a corner of a Parisian cemetery, where Alphonsine Plessis - Dumas's lost love, the Marguerite of his novel, the Violetta of Verdi's opera - is buried. And his mood becomes strangely soft and wistful for a man with such an antagonistic reputation.

"I've been to Alphonsine's grave in Montmatre twice, and I do find it quite moving to go and see her," he says. "She's in a very beautiful white sarcophagus, and people are still laying camellias on it now. A lovely little portrait of her is nailed to the marble It gets me all spooked and tingly."

Beyond the stuffy traditions that have plagued bad productions of La Traviata over the decades, "beneath the frou-frou" as he would put it, McVicar has found a personal way to get to the emotions within the story.

If he can bring some of this to the stage in Glasgow, then all eyes in the opera world will be on Scotland this week.