For Sir Bryn Terfel, one of the most valuable experiences of his early career came not in the form of a major opera-house debut, or a triumphant performance but in time spent with someone who had, as he says, “already been there and done that”.

Bryn Terfel. Photo © Mitch Jenkins

Terfel was then in his fourth year of training at the Guildhall School of Music and Drama, a talented but frustrated young singer who had yet to win a competition. Benjamin Luxon, the celebrated English baritone, came to work with the students, bringing not only his musical knowledge but a sense of style, presence and professional possibility.

“He was so charismatic, so good-looking, so incredibly well dressed,” Terfel recalls. “And talk about beards! His was just perfect, as if he had his own barber. Within three weeks, you could even see the fashion change in that room. We went from T-shirts and jeans to proper trousers, dress shirts and brogues.”

Fashion aside and more importantly, Luxon changed the way Terfel thought about singing.

“I was very boisterous then as a young singer. I knew I had a good voice, and I knew...