In perfect harmony

Angela Gheorghiu and Roberto Alagna's sizzling partnership is the stuff of legend. Which is why they're the hottest ticket in town this week

No husband-and-wife opera singer partnership - of which there are quite a few - is as celebrated as that of Angela Gheorghiu and Roberto Alagna. Don't even think about trying to get a ticket for any of the six performances of the Royal Opera's new production of Gounod's Faust. It sold out as soon as booking opened in February and the 67 day tickets held back are likely to be the hottest in town. Of course, it helps that Bryn Terfel is making his debut as Méphistophélès and that Antonio Pappano is conducting. But even against the starry ensemble, Alagna as Faust and Gheorghiu as Marguerite stand out as pretty sensational billing.

No husband-and-wife opera singer partnership - of which there are quite a few - is as celebrated as that of Angela Gheorghiu and Roberto Alagna. Don't even think about trying to get a ticket for any of the six performances of the Royal Opera's new production of Gounod's Faust. It sold out as soon as booking opened in February and the 67 day tickets held back are likely to be the hottest in town. Of course, it helps that Bryn Terfel is making his debut as Méphistophélès and that Antonio Pappano is conducting. But even against the starry ensemble, Alagna as Faust and Gheorghiu as Marguerite stand out as pretty sensational billing.

It's not just the voices, of course. Their lives have become the stuff of romantic legend, their relationship the focus of media attention, their behaviour criticised, their every appearance scrutinised. They met in 1992 when they were in La Bohème at the Vienna Staatsoper. Both were already married, she to a Romanian compatriot, a plumbing expert whose name she retains despite having severed the connection; Alagna to a wife dying of a brain tumour.

A train driver's daughter from Moldavia, she was brought up in Ceausescu's Romania, trained at the national music academy in Bucharest, and had become famous in her own country by the age of 18. When she reached London in the early 1990s it was only a couple of years before she was attracting rave reviews for her portrayal of Violetta in Verdi's La Traviata under Sir Georg Solti in 1994.

Solti recalled being reduced to tears on hearing her sing: "The girl is wonderful. She can do anything. She's extremely musical in that the music dictates her emotions, and that's something I've seen very rarely." TV bosses were so smitten that they cleared the schedule to relay the next performance live on BBC2. The accolade "a diva to die for" might have been coined for her. It has certainly stuck.

Alagna, 41 earlier this week (Gheorghiu is two years younger), took longer to establish himself. After all, unlike Gheorghiu, he hadn't been grooming himself for a life as an opera singer from the age of five. Growing up in Paris, to where his Sicilian bricklayer father had moved, Alagna's early career was spent in cabaret, as a South Bank Show chronicled, in repertoire ranging from Jacques Brel to "Nessun dorma" to the Israeli hora, "Hava nagila", as well as, reputedly, crooning in a pizzeria.

Winning the Luciano Pavarotti International Competition in Philadelphia in 1988 was a lucky break. Glyndebourne Touring Opera booked him to sing Alfredo in La Traviata and soon he was on the road, in digs round England. It was as Alfredo that he made it big at La Scala, Milan, in 1990. His career gradually took off and in 1994 he too was engaged at Covent Garden, in the romantic lead in Gounod's Roméo et Juliette. I remember thinking then that his ability to get right inside the role, as well as his precise French attack, was something very special indeed.

Anyone writing an opera plot couldn't have done it better. Both singers under the same opera house roof again... though officially their affair did not begin until later that year, after Alagna's wife died. They were married in 1996 by Rudolph Giuliani, between performances of La Bohème at the Metropolitan Opera in New York.

And lived happily ever after? Well, they've been a fixture on the world's most prestigious stages, on CD, on DVD and more recently in film versions of both Tosca and Roméo et Juliette. Gheorghiu has shared girly talk about how they make love before performances to relax their vocal chords. It was Alagna who was cheering loudest from the stalls when his wife sang in the Last Night of the Proms last year, an over-the-top appearance that she milked for all it was worth.

She switched record companies to share the same label as her husband and EMI lost no time in issuing an album of love duets. In true Italian style, Alagna wanted his brothers to be part of his life too, offering their services as opera designers to the Metropolitan Opera in New York (seriously), signing them up to strum their guitar accompaniments for him on a CD of serenades and even commissioning an opera from one of them.

The couple have garnered reputations for terrific performances, Gheorghiu in particular, but also for being terrifically difficult, Gheorghiu in particular. She belongs to the old school of prima donnas, grand to the extent, I heard, of automatically expecting hair-dressing and make-up assistance for a Radio 3 interview.

They've aroused strong emotions in those with whom they work. The director Jonathan Miller wasn't joking when he nicknamed them Bonnie and Clyde, and while opera critics have praised Gheorghiu's lyrical beauty, gorgeous tone and "classy" act, Alagna doesn't attract quite the same admiration, his light voice good in some roles but, as the same critics have suggested, more limited.

When Miller's production of La Traviata had Violetta dying in a hospital ward (away from the theatre, Miller is a doctor after all) she dug in her heels, declaring, "I die alone!" Robert Wilson's minimalist concepts aroused their contempt and, though both singers claim they're merely trying to ensure quality control, Gheorghiu is adamant that "everyone goes to the performance to see Angela and Roberto, not Robert Wilson".

They withdrew from performances in Vienna after Gheorghiu saw the production on television - not the only time they've disappointed opera-goers by dropping out. On tour with the Met in Japan, Gheorghiu - as Micaëla in Carmen - took exception to her wig. Joseph Volpe, the Met's feisty general manager decreed, "That wig is going on with or without you." The wig went on, and so did Gheorghiu but she managed to cover it completely with her hood. I've seen her exert authority over a musical director when, at Monte-Carlo Opéra, she lost her way in the Cherry Duet in Mascagni's L'Amico Fritz. Alagna froze on the opposite side of the stage while, to the audience's astonishment, Gheorghiu stepped out of role and had a brief but imperious and definitely one-sided conversation with the conductor.

Alagna, who charms and disarms with his open, smiling face, and Gheorghiu, whose dramatic looks, flashing eyes and long dark hair command attention, are a handsome couple. They're only making the most of their match artistically, some would argue, rather than cynically capitalising on it. Self-conscious, a bit prickly and anxious to keep their home life private, they're not so different from other celebrity couples today. Their home is in Geneva and they are joined when possible by Alagna's daughter from his first marriage and Gheorghiu's orphaned niece, whom she adopted. Unlike that other golden couple, Posh and Becks, at least Gheorghiu can sing while he "likes staying at home, being with family".

Are they such a phenomenon though? Other husband-and-wife operatic marriages haven't caused anything like such a stir, perhaps because they've not been between such an ambitious soprano and acclaimed tenor or because both parties haven't cultivated such glamorous images. Two of the finest Wagnerian singers of the 20th century make up the husband and-wife team of Thomas Stewart and Evelyn Lear; one of today's best young baritones, the Canadian Gerald Finley, is married to soprano Louise Winter, while soprano Claire Rutter is happy sharing the spotlight with her husband, the baritone Stephen Gadd. And an encounter between the English tenor Philip Langridge and the Irish mezzo Ann Murray when they appeared in Cavalli's Eritrea at the Wexford Festival led to a long and happy marriage. One of the best recordings of Boito's Mefistofele featured Mirella Freni as Marguerite; the evil spirit was sung by her husband Nicolai Ghiaurov (who died last week).

And what could be more romantic than Dietrich Fischer-Dieskau's proposal to Julia Varady when both were in Puccini's Il Tabarro. "He was playing the barge-owner Michele and I was his wife, betraying him with another man. Right before the end of the opera, in the scene where he slowly strangles me, he slipped a note into my hand that read: 'Will you marry me?' When I read that I was so astonished I nearly missed my cue," she recalls. Subsequently both singers preferred to be booked together, just like Gheorghiu and Alagna who - married while young, not yet at the peak of their careers - strike a chord even with people who never go to opera.

The Royal Opera's 'Faust' opens tomorrow (returns and day seats only, 020-7304 4000, Covent Garden, London WC2) and is broadcast live on BBC2 and in Covent Garden's piazza on 19 June, from 6.30pm