Prince Charming played by a woman? It may sound like the Christmas panto, but this is midsummer at the Royal Opera House and the Cinderella in question is something quite different. Jules Massenet's Cendrillon is a French romantic take on the fairy tale – one that is scarcely ever performed and is now coming to Covent Garden for the very first time. The British mezzo-soprano Alice Coote has fallen under its spell. She is starring in the trouser-role of Le Prince Charmant and, pausing for a cup of tea during rehearsals, she says she can't get the melodies out of her head. "I've never been in a show before where I've woken up each morning singing another character's tunes," she declares.
The Prince is the latestof many so-called "trouser-roles" that this most modest of opera stars has taken on. Coote, 43, has enjoyed a much-praised career for some 20 years and, inevitably for a mezzo, has run the gamut of opera's male characters for female voices, from Handel and Mozart to Strauss's Oktavian in Der Rosenkavalier. But Massenet's Prince is anything but a step backwards. Instead, the radiant score offers her the chance to let rip – appropriate, now, since her voice, she says, is changing, "becoming bigger and higher". It also presents the rare necessity to sing duets with another mezzo-soprano: the American megastar Joyce DiDonato, who is Cinderella. "Our voices seem to blend well and it's great fun singing and acting together," Coote enthuses. "It might be the only chance we ever have to do so."
Her previous experiences at the Royal Opera House include one that was less happy: in 2003, singing in Handel's Orlando, she suffered a haemorrhage on her right vocal cord and had to pull out of half the run. Since then she's found herself constantly charged with having had a "turbulent" career.
"It's not recognised nearly well enough that singers are just like athletes," she points out. "The voice is part of the body. If an athlete falls over in a race, the commentators will usually know if, for example, her preparation time has been affected by an ankle injury. But so many high-profile singers have been punished by people writing that they're finished or should be given up on, just because they've had an injury or an operation. If you're going to sing for 25 years, it's bound to be an up-and-down process." Once an up and a down came simultaneously: in 2005 when she sang Oktavian in Los Angeles, the company's director Plácido Domingo singled her out for praise in a speech after opening night and asked her to step forward. She did so, tripped, and ended up with a slipped disc.
Her path has had plenty of highs and lows. She comes from rural Cheshire and grew up, the youngest of three children, in a house filled with music – her father, an artist, used to play BBC Radio 3 from breakfast time onwards in his studio. Coote was drawn to music early on and learned the oboe, but describes herself as a painfully shy child. "Even at social gatherings with our grandparents I'd want to stay in the background," she says. "But music brought out the core of who I am and got me into a situation where I could stand up and perform in a school concert, which I'd never have done otherwise. There was something inside me that just knew I had this voice."
Soon her teachers knew it too: even in her mid-teens, she says, her voice sounded relatively mature and she was advised that if she took it seriously enough, singing could become her life. At 18 the country girl headed for the capital to study at the Guildhall School of Music and Drama, but she hated living in London so much that she didn't finish the course and retreated north: "I had a terrible time at college, but I always had this thread of belief that singing to other people is what I should do. Expressing emotion through sound is what comes naturally to me and where I feel most myself."
After taking a succession of jobs in shops and offices, studying singing privately on the side, she pursued further studies at the Royal Northern College of Music and then the National Opera Studio. Further obstacles arrived one after another: first, she had to have her tonsils out, then she was injured in a motorway car crash en route to London to join the NOS. But at the RNCM she found a true mentor in the great German mezzo-soprano Brigitte Fassbaender, who gave her the confidence she needed so much.
"She's the real deal," Coote says. "It was incredible to meet such an icon, and to hear her say in front of everyone at the RNCM, when I was still struggling, that I had major talent. She flew me over to her house for more coaching, put me up, cooked me meals, gave me self-belief. There's a thread about her through everything I've done – from meeting her before I even knew I could have a career, to being asked to sing Oktavian in Munich in the production in which she used to sing that role, and putting on the same green velvet shorts."
Until now fans have often seen Coote as the perfect mezzo for Mozart and early music. But now her expanding voice is enabling her to branch out – in recent seasons she's sung much more Strauss, plus Carmen, and Charlotte in Massenet's Werther – and her spell of injury, she says, has borne positive results, giving her an increased understanding of her voice's needs.
"I feel that I've finally learnt how to sing." She laughs, but there's a serious undertone. "I'm itching to sing bel canto opera, which I've hardly ever done: Donizetti, Bellini and Gluck. I'm equipped now to take on bigger challenges. I feel like I haven't even scratched the surface."
Shy she may have been, but nothing will keep that voice from finding its way forward. Meanwhile she heads home from rehearsal to the countryside for some well-earned rest, happy after five months on the road to hear nothing but silence and birdsong.
'Cendrillon', Royal Opera House, London WC2 (020 7304 4000) 5 to 16 July