Hitting the high notes

Three maidens enter on tiptoe and light candles around Somnus, god of sleep, as he snores in his cave. He opens an eye, is instantly aroused, and bursts into song, causing fluttering mayhem all around. "Again!" calls the rehearsal director. "But this time, play up the horrified excitement."

The maiden-in-chief, Iris, has only a couple of lines, and they're exquisitely delivered, but what you notice more is the comic timing of her gestures. For this young singer, currently on Covent Garden's Vilar Young Artists Programme (VYAP), a bit-part in Semele is par for the course, but in the pivotal role of Pamina in Die Zauberflöte tonight, Sally Matthews will be the focus of much interest. It won't be because she's very obviously pregnant (though she is); it will be because, since her blazing success when called in at the last moment to cover as Nannetta in Falstaff, she is increasingly being talked of as the next Kiri Te Kanawa.

Critics have reached a rare unanimity on Matthews' high pianissimi, and her bel-canto line, and there's one adjective they regularly deploy: "It's become a standing joke among my friends," she says, with a bemused shrug. "People always say my voice is 'creamy' - every bloody crit." So how would she herself describe it? "Lyrical. And also musical, because phrasing is very important to me. I'm happier being respected by instrumentalists than I am by singers, because players are listening for many things beyond the noise and the size of your voice. And mine isn't very big."

This is accuracy, not modesty: later in our conversation, she admits that she wasn't initially overjoyed to be doing Pamina, "because the first act didn't really show off the parts of my voice that I really love". That's the right relationship between a singer and her voice: a fine romance.

Sally Matthews' parents encouraged her aspirations from the start - her father was a failed rock singer - and though she danced from the age of three, her romance started when she began singing lessons at 10. "I've always been dyslexic, and it can still crop up as a problem, particularly with the meaning of foreign words. Words I've sung a million times, such as quando, or musical instructions such as andante or allegretto. Richard Branson apparently has the same kind of dyslexia, though with him it's words such as "net" and "gross" - bizarre!

"At school this made me feel stupid, and I was always at the bottom of the class. Singing was the one thing I was good at, so music came to my rescue. Luckily, I was allowed to excel in it."

When she was 12, she won a singing competition for under-18s, and she routinely starred in musicals, appearing as Eliza in My Fair Lady when she was 15. She was, she says, instinctively careful with her voice: no clubbing or discos, and always on form for the next piece of coaching. It was no surprise when she got a scholarship to the Guildhall School of Music, or that she carried off the Kathleen Ferrier award when she arrived there.

Was the Dame Kiri comparison a surprise? "I was blown off my feet. But I've not listened much to other people. I've got a good ear, and sometimes I've realised I've come out with sounds that I've copied from a record - it wasn't me at all. I was never very keen on listening - I just wanted to create for myself."

But she admits to being competitive. "I like to win. You have to be competitive, in a healthy way, without kicking anyone in the teeth to get what you want. Basically, I'm competing with myself. If I don't do an audition well, I beat myself up about it."

This is emphatically corroborated by Tisi Dutton, who runs the VYAP: "If Sally is part of a group on stage, she's the one you watch - she's got the x-factor. She has the facility to take you to places you're not often taken to." Paying these young singers £20,000 per year, training them intensively in every aspect of their craft, giving them small parts to sing, but big ones to cover, the Royal Opera House has found an ideal way to nurture new talent. Occasionally, one of its meteors goes prematurely into orbit - such as the Lancashire tenor Alfred Boe, headhunted by the film director Baz Luhrmann to star in the Broadway La Bohème - but most are happy to mature away from the spotlight. "This is a ferociously competitive world," says their coach, David Gowland. "When they start doing well, I tell them, just remember there's always someone younger and better waiting to take your place."

Just as Matthews did when she leapt into the role of Nannetta; and as a dashing young Lithuanian tenor named Edgaras Montvidas may yet have to do in Semele, if the principal singing Jupiter should unwisely fall sick (until then, Montvidas is singing Apollo). Montvidas so regularly finds himself called upon to step into the breach that he has begun to arouse curiosity: "My friends ask what my secret is," he says, with a laugh. "Am I putting poison in their drink?" It would be crass to say that if Matthews is the new Kiri, Montvidas is the new Pavarotti (though he has in fact had one heady tutorial from the master). Montvidas's may never be a "great" voice, but his brilliant tone, and his persuasive stage presence mark him out as a performer in a class of his own.

"When he auditioned, he was shy and withdrawn," says Gowland. "He wore a black suit, and stood stiffly to attention: very Eastern bloc. But when he sang Lensky, though stylistically it wasn't what we expected, I was just enthralled by his sound."

The tall, poised individual whom I meet today talks with wry amusement about how he came to be where he is. He began playing the piano at 10, and proved good enough to get into the conservatoire with it, but, deciding that he would never be a great pianist, he looked for a career in something else, and settled on singing as a soft option. "I thought you just had to learn the words and sing them. I'd never seen any opera, and I'd always thought singers were strange people, a bit mad, always screaming - it seemed a very artificial thing. But it turned out to be like a drug. Once you start, there's no going back."

He has become noted for his meticulous preparation before a role, but he has bypassed the counselling that is one of the optional extras on the course. "How to deal with stress, with being away from home; how to cope with fame - I refused to go to that class," he says. "Some people apparently found it helpful, but those things are not problems for me." As one of the students who linked arms to defend Vilnius's radio station against the Russian tanks in 1991, Montvidas comes with an altogether tougher attitude than his cosseted Western colleagues. Having jumped through all the obligatory Communist hoops - joining the Pioneers in adolescence, for example - he was energised by his country's liberation, and he now positively radiates that quality. "My voice is everything about me, it reflects every aspect of my life. If I go to a movie, or see an exhibition, it will affect my voice. It's much more than an instrument. You can treat your voice either as two strings that make a noise, or you can treat it as a way of life in itself."

This is a young man, you feel, who is up for anything - he has even appeared projected on to the National Theatre's walls, as part of the artist Sam Taylor-Wood's video Mute. And yes, he, too, is unashamedly competitive. "I'm jealous. I feel: I could do that, why don't they choose me? But it's a white jealousy, not a black one such as when you would put something in your rival's drink!"

Nicely put. But I still think that Jupiter had better look out this week, when they all go down the pub.

'Semele', to 11 July (Edgaras Montvidas sings Apollo; Sally Matthews sings Iris); 'Die Zauberflöte', to 9 July (Sally Matthews sings Pamina tonight); Royal Opera House, Covent Garden, London WC2 (0207-304 4000)