Angela Gheorghiu: 'My husband is jealous of my new leading man'

Angela Gheorghiu has been Covent Garden's reigning diva ever since her 1994 Traviata famously reduced her conductor, Sir Georg Solti, to tears. When the Romanian soprano got engaged, a year later, to the French-Sicilian tenor Roberto Alagna – Rodolfo to her Mimi in La Bohème – all hell broke loose in the press, and the couple fed the frenzy by talking about their pre-performance love-making ("to relax their voices"). Mayor Giuliani, an opera fanatic, married them in New York, they signed with Charles Aznavour's agent, and they rushed out an album of love duets – but the adulation was far from universal. "The Ceausescus" was an epithet applied to the couple (Gheorghiu is Romanian), but the one that stuck was Jonathan Miller's "Bonnie and Clyde" – bestowed in rage at their capricious antics while he was trying to direct them in Bohème. But while Alagna's voice is now showing signs of wear, nothing has dimmed the unique gorgeousness of Gheorghiu's sound, nor the fire she brings to her roles.

Interviewers of this monstre sacré tend to come away with the prepared speech for whatever show or record she's promoting, and with lacerations if their questions are, in her view, out of line. One knows, for example, that she absolutely won't speak about her sister's death in a car crash in 1996, the shock of which has impelled her father to retreat permanently to a monastery on Mount Athos. Her cousin Florentina has fixed our interview in a London hotel, and the figure who eventually materialises is nothing like the glamorised fashion-plate one has been led to expect: this Gheorghiu is a rock-chick – hard-bitten and very Balkan.

She hasn't yet decided which arias she will sing in the Southbank recital which is the pretext for this interview (in the event, it's to be a selection of arias by Verdi, Massenet, Gounod, Mascagni and Puccini). But she's fired up by the Tosca which Covent Garden created as a vehicle for her, and which, as we speak, has just had its first revival. (Indeed, Gheorghiu will return in La Traviata next July at the Royal Opera House.) She wishes the audience could have seen up close the murderous electricity between her and Bryn Terfel: "I just trusted my instinct, as I always have. In 20 years I have never made one mistake in following my instinct." Forty-year-old memories of Maria Callas in the role have been erased: "Now everybody accepts me as Tosca."

One thing leads obliquely to another in Gheorghiu's rapid discourse, and suddenly she's criticising Jonathan Miller, as an example of what a director should not be. "Imagine the National Theatre engaging a director for Shakespeare who doesn't speak a word of English – yet in opera it happens every day. I remember Jonathan Miller coming to direct a new production of Traviata holding the booklet from my CD – excuse me! Whoa!" Was he perhaps wanting to flatter her? "Unfortunately not. He is a doctor, so he set the last scene in a hospital – he wanted to put a lot of beds, and I said no, put only one bed – my bed." What does she want from a director? "They must not be afraid to make demands. They must not be so touched by my singing that they just cry, and accept things as perfect. But they must ask, not command. If they command, I go." She prepares with fanatical thoroughness for each new role at home in Geneva, where she and Alagna have brought up her sister's orphaned daughter, Uana, alongside Alagna's daughter, Ornella, from his first marriage (his wife died of cancer).

Gheorghiu reminisces happily about the good things in her early life: the dresses her mother made for her and her sister – "we were like models walking down the street" – and the duets she and her sister sang at concerts. At school, she had the loudest voice, but also the most mature: "I was born with the right impostazione [vocal structure] for opera." Has her voice changed over the years? "Never. I have taken care of my instrument – I always have known my limits, not to sing too much, too loud, or too high. Wagner would be bad for me. I love his music, but he has no knowledge of voices. Being a singer is like being a painter, putting the right colour exactly where you need."

As she discusses – with notable generosity – the individual strengths of her colleagues, it becomes clear that in matters of the voice she is a real connoisseur. But one with an eye firmly fixed on the bottom line: "Opera is like football. Eleven players all dressed the same, but all the time you look at only one. Because he has that aura. His playing may have a defect, but he turns that defect into a strength." Does this apply to her too? "Yes." What's her defect? An exultant shout: "To be different! Whatever I am doing, people are looking at me – but they don't know why!"

How does she feel about all the knocking stories in the press? "First I cried, then I said, I'll call my lawyer. But then I thought – the press have a lot of imagination. So I say, thank you for the ideas! They call me 'Draculette' because I am from Romania. And they talk of Roberto and me as Bonnie and Clyde – OK! Those names are now the subject of operas. Draculette is already written, by an American composer, so I say to the press, thank you very much. Another composer is now writing Bonnie and Clyde – so, thank you again!" What about that oft-repeated tale of her demanding a make-up artist for a Radio 3 interview? "Lies!"

The latest piece of mendaciousness arose, she says, out of an interview Alagna recently gave in London, in which he was reported as being jealous of her new artistic partnership with the German tenor Jonas Kaufmann (she now divides her time on stage between them). But that report seems to have been pretty accurate.

"In the beginning it was easier to sing with Roberto, when our repertoire was mostly the same, but then I began to sing with others, and in Roberto's mind there is jealousy," she says. "I'm a good colleague, I try to support him. But at the same time I am an opera singer, and I want a good result with everybody – if others want to sing with me, I try to give them the same. I need to feel free, to sing where I want, with who I want. I didn't marry Roberto to sing only with him. I must go ahead with my projects. And he is very upset."

What will she do to resolve this? "Nothing. The show must go on, the life must go on. I must feel free. The problem is that we are married, and his mind is like, 'I must do with Angela everything.' He's a very good singer, and I am not betraying him, but he must accept that I will sing with more people. And here is the problem! The person who is happy because you are happy – that person loves you. But Roberto is a Sicilian man, so he has in his blood, 'She's mine – only mine!' He's still singing my old repertoire, but I'm not singing his repertoire."

Might the answer be a long holiday together, to sort things out? "He never takes holidays! In 15 years, I have had just one holiday with him – in Mexico; it was paradise. But he is so intense about his profession, he won't stop." A rueful shrug: "C'est la vie!"

She reads her interviews, she says, but not her reviews. "Each review is of just one performance. It's an opinion written fast, about something I worked so long on, and after a performance I know how bad or how good it was – I have my internal critic."

Maybe, I suggest, reviews are now less of an issue than they used to be, given that most newspapers are primarily obsessed with gossip. "And I'm very good for that! I'm top of the list – thank you very much! You and I can thank each other, finally." The interview finished, I turn my machine off, and she suddenly asks with shy urgency what I thought of her Tosca the night before, and is grateful for a positive response. Perhaps reviews do matter after all.

Angela Gheorghiu will appear with James Valenti and the Philharmonia Orchestra at the Royal Festival Hall, London SE1 (0871 663 2590, www.southbankcentre.co.uk ), on 2 October at 7.30pm. She will return in 'La Traviata' at the Royal Opera House ( www.roh.org.uk , 020 7304 4000) in July 2010

The high notes: Gheorghiu's greatest recorded performances

'Madama Butterfly' 2009

Released earlier this year, this recording presents Gheorghiu – partnered by the German tenor Jonas Kaufmann – in the role which she insists is too strenuous for her to tackle live on stage. And you can see why: maintaining a performance of this standard over the full length of this demanding work really might endanger her voice.

'Verdi Per Due' 1998

This was the album, with dreamily kissing faces on the cover, which established Gheorghiu and Roberto Alagna, who married in 1996, as opera's reigning royal couple. That they were accompanied by Claudio Abbado and the Berlin Philharmonic was a further badge of class.

'Casta Diva' 2001

Gheorghiu tackles the supreme soprano roles by Bellini, Rossini and Donizetti – and she does so with her usual consummate artistry.

'La Traviata' 1994

Under the baton of Sir Georg Solti, with Frank Lopardo as Alfredo Germont, Leo Nucci as Germont père, and the orchestra and chorus of Covent Garden, this was the recording which first introduced Angela Gheorghiu to the wider world in 1995. She is set to reprise the role next July.