Simon Keenlyside is relaxed when we meet in his dressing room at The Royal Opera House, despite his left arm being immobilised following some serious ongoing muscle repair. Given that he is one of this country’s most sought after singers he comes across as genial and self-effacing – a far cry from one’s perception of a profession that is populated with its fair share of over-sized egos. He has sung many of opera’s leading baritone roles including the Count (Figaro), Don Giovanni, Papageno (Magic Flute) and has more recently added ‘heavier’ roles to his repertoire including Wozzeck, Posa (Don Carlos), Rigoletto and Macbeth, which following a critically acclaimed debut in the role in Vienna, he is about to sing in London with The Royal Opera for the first time.

His early singing career came about by default “I was packed off by a musical parent to one of those musical schools, St John’s Cambridge, and my life wasn’t too dissimilar to how it is now. I found myself travelling to America, Canada, Europe and Australia with the choir in the 60s when I was a boy, and it was very much the same life as today. We recorded for Argo and Decca. It was an odd childhood from the age of eight to fifteen but I loved it.” He admits that he had somewhat of a dysfunctional background and that singing was sometimes more of a consolation than joy, but it was his love of singing that motivated him to study at the RNCM for four years once he had finished his Zoology degree, and then moved to Germany to learn the language.

“As I was such a fan of German lieder my teacher, a fantastic man called John Cameron, advised me to go and live in Germany so I could learn the language which led to me being engaged by the Hamburg opera. Being part of an ensemble in an opera house is great for your development as a singer as you learn your career very slowly, singing the minor roles to begin with but you’re adding roles all the time and it’s the best way to learn your trade. It’s a great system – you get paid for it and at the end of the day get to go home to your own bed.”

Considering the high profile career that Simon has enjoyed, there must have been many highlights, but for him the standout moments have taken place away from the limelight. “I had incredible luck in Salzburg as I had won a Richard Tauber competition but rather than studying with Sena Jurinac I went and did a language course for three months, but there wasn’t enough money in the prize to keep me there. I was staying in a hostel and singing in the woods at night as there was nowhere else to sing. I tried to get into the Mozarteum in Salzburg to ask someone’s advice but the guard wouldn’t let me in, then one day he wasn’t there so I slipped in and heard a vocal class.” Simon spoke to the teacher, Rudolf Knoll, who after having heard him sing six bars of the Barber of Seville instructed him to come back, which he did every day for three weeks becoming part of the class. “He asked me for nothing and introduced me to Mr Busse from the Hilbert Agency who sent me to audition in Graz, Bremen and Hamburg and got me my first job.”

Talk turns to Verdi, and Macbeth in particular, which is usually associated with big dramatic Italian voices, but as Simon has essentially been singing lyrical baritone roles until recently I’m keen to find out how this progression has come about. “I could have been comfortable travelling round the world with five roles in my back pocket, and made a fortune, but that’s not what I’m about. I’m a very cautious man and I have stepped very slowly into the Verdi repertoire via the role of Germont in La Traviata which is quite short, then Posa in Don Carlo. I tried them out many times and thought to myself ‘Am I being realistic or am I being an idiot?’ The problem is that many journalists will listen to a fabulous post war American baritone with the volume turned up, but there are a dozen other ways to skin a cat.”

He rightly points out that if you listen to Leonard Warren, Leo Nucci, Robert Merrill or Giuseppe Taddei singing Verdi they will all sound utterly different “and that gives me confidence to think ‘well it’s OK as I’m not trying to be something that I’m not.’” Given the fact that he is adding heavier roles to his repertoire he is keen to keep a mix of old and new roles adding that he doesn’t want to relinquish roles such as Papageno. “I’m not changing repertoire as I’ll never bore of The Magic Flute but I don’t want to go round the world month after month, year after year hammering my voice, but nearly all singers encompass thicker roles once they reach forty as I have done and I don’t want to sing them all either. I’m just seeing how it goes, one after another.”

He is particularly excited to be working on Macbeth with Antonio Pappano who pays scrupulous attention to Verdi’s markings in the score. “Orchestras play louder and higher than in Verdi’s time, so it’s the conductor’s job to keep the orchestra in check and from playing too loudly. I know Mr Pappano loves his Italian repertoire and is considerate of singers so I know that I won’t need to ‘shout’ all the way through. The hardest thing about the role of Macbeth is finding the right colour for the character. Once you find that, the character will follow and I know I won’t please everyone, but I’m going to hold my nerve. I have spent a lot of time studying the history of this role and other roles and I’m passionate about what I know to be valid and viable, and that gives me the validation to encompass these types of roles. I won’t be trying to emulate some of the more muscular sounding exponents of the part, but will be doing it within the scope of what I am able to deliver. You know, I can’t make sense of this ludicrous, chaotic riot called life, but music helps me a lot.”

Simon Keenlside sings the title role in The Royal Opera’s revival of Phyllida Lloyd’s staging of Verdi’s Macbeth from 24 May. www.roh.org.uk