Mezzo-soprano Sophie Koch is one of the leading French singers of her generation, and audiences in London have been fortunate to see her in many of her most famous roles at The Royal Opera including Cherubino (Le Nozze di Figaro), The Composer (Ariadne auf Naxos), Angelina (La Cenerentola) and more recently Brangaene in Christof Loy’s thrilling staging of Tristan und Isolde. She is back to perform one of her signature roles, Charlotte in Massenet’s Werther, alongside Rolando Villazon, and I caught up with her the morning after the general rehearsal.

Many singers had idols when they were growing up and Sophie was no exception: “It started with Maria Callas and Kathleen Ferrier, but the singer who influenced me most was Christa Ludwig.” During her teenage years Sophie didn’t take up singing, instead she learned the piano, yet this didn’t stop her from wanting to be part of the choir at the Sorbonne in Paris where she was studying: “But I was not accepted, because I auditioned as a soprano and they said ‘you have no high notes’, so I just assumed that I couldn’t sing, but my mother suggested that I take singing lessons, and before long I met with Christa Ludwig and she gave me an enormous amount of encouragement. I mean I couldn’t sing, I had no technique but I persevered and at the advice of Christa I auditioned for the opera school at the Bastille, Paris and I was accepted for six months, but didn’t make it into the young artists’ scheme because I still had no technique.”

She was determined to follow a career in singing so enlisted at the Paris Conservatoire and began singing lessons with the legendary French mezzo-soprano Jane Berbié (who remains her teacher to the present day), and four years later won first prize in the Dutch International Singing Competition in Hertogenbosch. Not only was Christa Ludwig a major influence in Sophie’s decision to become a singer, but she also cites being introduced to Jane Berbié as one of the most important stepping stones to forging her singing career. Another milestone was when she auditioned for The Royal Opera’s head of casting, Peter Katona. “It was 1996. I had told my agent that I just didn’t want to perform at home, but wanted an international career as well. At that time I knew that Mr Katona was only really interested in established singers, but my agent was very influential so I got the audition. I was surrounded by very confident singers, so I auditioned then left as I had to catch my train back to Paris.”

Sophie had obviously made a big impression as Peter Katona came running after her and told her that he needed to talk to her. She auditioned for the roles of Composer, Angelina and Dorabella,(Cosi fan tutte) all of which she subsequently sang for The Royal Opera along with Rosina (Il barbiere di Siviglia) and Cherubino. Of course, like all singers, her voice has developed over the years, which has allowed her to add ‘heavier’ roles to her repertoire. She was outstanding as Brangaene in Loy’s staging of Tristan und Isolde here a couple of years ago and has recently sung the role of Fricka (Das Rheingold) in Paris. Next season sees her role debuts as Venus (Tannhäuser), also in Paris and Fricka (Das Rheingold and Die Walküre) and Waltraute (Götterdämmerung) in Munich’s new Ring Cycle. “These new roles are a natural development for my voice. If you want to have a long career it’s very healthy to start with lighter roles, to know how to sing and to take care of your voice and then when you get stronger she can think of heavier roles, but it’s something you need to approach with care.”

Talk inevitably leads to French opera and the role of Charlotte which she sings for the first time in London opposite Rolando Villazon’s Werther, although they have sung these roles together before in Vienna. It’s evident the role of Charlotte is dear to Sophie’s heart as she has also sung it in Paris, with Jonas Kaufmann (this performance is available on DVD from Decca) and in Madrid in the last year, but like all roles makes specific demands on the singer: “Vocally you need to sing with youth and freshness in the first half and then being able to give a more dramatic accent in the second part – that is the main vocal challenge and the character is light and young to begin with and then more serious and grown up later on, but of course in order for it to work well you have to be able to have a good partnership with the tenor. You have to give a lot – I’m fortunate that I have sung this before with Rolando as it’s very important to know your partner well and to trust him.”

Although we touched on Sophie’s future engagements I was keen to find out which roles were on her wish-list and not surprisingly, given the fact that she is singing more Wagner these days, the first role that came to mind was Kundry (Parsifal): “This role is absolutely a natural progression for where my voice is going - but in the next ten years. Gerard Mortier also offered me the role of the Nurse in Die Frau ohne Schatten but around that time, in about four years, I am scheduled to sing roles such as Alceste and when you sing something like Kundry or the Nurse there is no going back. If I want to sing Octavian again, maybe for the last time in five years’ time, I have to take care. I think Kundry is a role for the last ten years of my career, but not now.”

Sophie Koch sings the role of Charlotte in The Royal Opera’s revival of Werther from 5 May, 2011. www.roh.org.uk