Christine Rice's DPhil concerned the reflection of light from clouds. But there's nothing reflected about the glory that now surrounds this Mancunian mezzo-soprano. In Harrison Birtwistle's new opera The Minotaur, the premiere of which is at the Royal Opera House on 15 April, she stars as Ariadne; it offers her an intellectual challenge of a kind far removed from her studies in physics, as well as making the most of a voice that increasingly bewitches listeners with its versatility, power and beauty.
Backstage between rehearsals, Rice, 37, is energetic, down-to-earth and good-humoured. She has to be: she juggles her operatic commitments here and abroad with life as a mother-of-three based at Rugby school, where her husband is head of modern languages.
And if the public thinks that it's the sopranos who have all the glamour, that's not a problem. "I have no complaints about being a mezzo. I think certain types of soprano have a shelf life because they're put into young, girlish roles and there can be a certain credibility gap as you get older – whereas mezzos are caught between playing the young boy and the old bag! And as you head towards your old-bagdom, you can embrace a great variety of music."
Rice's rise may look meteoric, but she insists it's been a gradual process of "plugging away". Over the past decade, she has sung everything from Monteverdi to Thomas Adès, from Handel trouser roles to Rossini's La Cenerentola; she's also been a BBC Radio 3 New Generation Artist. Her debut album on EMI featured five composers and three languages, including the baroque purity of her beloved Handel and the heady sensuality of Duparc. And if the future holds meaty parts like Oktavian in Der Rosenkavalier and the formidable mothers-in-law in Janácek's operas, that will all be well and good.
As the daughter of a chemistry lecturer, Rice thought a career in science would be the way forward, but she nurtured a passion for theatre and music. "All my siblings did science A-levels and I just wanted to be like them," she recalls. "At that time, the late Eighties, unemployment was still high and the careers advice was to do sciences so that there'd be more likelihood of a job at the end of it." She went to Balliol College, Oxford, for a degree in physics, and subsequently began a DPhil. But in the end, she decided, "It wasn't really for me – I didn't quite fit."
Rice elected to spend a "gap year" at the Royal Northern College of Music. "I didn't assume I'd make anything of the singing career-wise, but I was very fortunate. I met a wonderful teacher, Robert Alderson: he had an ear for an untrained voice, and thought I had the potential to be a working singer, so I stuck with him – and I haven't looked back."
Her first singing job was in the Glyndebourne chorus. Soon after, she joined English National Opera under contract for four years. She was to have sung in Monteverdi's L'incoronazione di Poppea there last autumn, but instead took time out to have her third child, William. She'll be back there later this year singing in Handel's Partenope: "I do a lot of Handel. He's the greatest."
She convinced that career trajectories aren't a question of one big break: "That's the trouble with these TV programmes where it's featured as a sort of one-off competition. In fact, every time you stand up, you are part of a competition and you're judged by how you sing on that day."
Still, one individual in the right place at the right time can make all the difference. Antonio Pappano heard her at the Théâtre de la Monnaie in Brussels, shortly before moving to Covent Garden as music director. "Peter Katona, the main casting guy here at the ROH, had me in mind for a few things," says Rice, "but Tony came to see a performance and he took a shine to my voice. So there was sort of an agreement between Peter and Tony that I was a useful singer. I'm such an admirer of Tony's. He's often associated with romantic Italian music, but in the Birtwistle he is doing absolute cutting-edge contemporary music, and he's fantastic. He has a total understanding of the voice and the orchestra as a pairing."
Birtwistle's music is notorious for its grittiness and complexity – this is the composer whose work for saxophone and orchestra, Panic, induced scenes resembling its title at the 1995 Last Night of the Proms. But in recent years, Birtwistle may have mellowed a little. "In the rehearsal room we've all been thrilled by it," Rice says. "There's a lot of variety of texture and transparency in the music, with some very beautiful, sort of silvery sections. And I think the special effects in the theatre are going to be fabulous as well."
Still, she adds, the sound suits the subject: "There's a visceral, violent quality to some of his music and it's a very bloody story. There aren't many jokes. He has created a dark and disturbing world for a dark and disturbing myth.
"David Harsent's libretto is quite complex psychologically: everyone has their own needs and their own agenda that they're pursuing and these come into conflict or harmony, depending on the point in the plot. The libretto is very clear – it's poetic in its use of language, but so strong that there hasn't been much difficulty interpreting it. It takes a sympathetic view of all the characters – everyone is trapped in their own prison and seeking freedom in some way."
The character of Ariadne is certainly rewarding :"Her journey gives you a lot of scope and a lot to think about." Is that her favourite kind of role? Yes, but also no: after the run, Rice is off to Munich for a rather different experience, singing Dorabella in Mozart's Così fan tutte. "That's completely the other end of the spectrum – in terms of the female psyche, it's about as silly as you can get," she says. "There's a thrill to performing tragedy, but there's also a thrill to performing comedy. What's nice is to be able to do both."
'The Minotaur', Royal Opera House, London WC1 (020-7304 4000), in rep 15 April to 3 May