It was in Cardiff, and the cast was 60 per cent Welsh-speaking. It's the first time I've walked into a rehearsal room speaking my mother tongue, which in itself was a breath of fresh clean air from the Welsh mountains. Singing Hans Sachs is always a milestone, but I was happy to be part of such an achievement, not personally but as a company.

Terfel took on the role of Wotan for the premiere performances of Robert Lepage's new Met staging of Wagner's Ring 2010-12. His international operatic career began that same year when he sang the Speaker in Mozart's Die Zauberflöte at the Théâtre de la Monnaie in Brussels and he made his United States début as Figaro at the Santa Fe Opera. On 17 July 2010 the cast of this production gave a "concert staging" at the Royal Albert Hall as part of the 2010 BBC Proms which was broadcast on BBC Radio 3 and on BBC Four television.

Terfel was initially associated with the roles of Mozart particularly Figaro and Don Giovanni but has subsequently shifted his attention to heavier roles especially those by Wagner.