It’s very interesting to consider what sort of voice should sing Wotan. Mine was always considered too low for the part – I spent the first 17 years of my career singing the bass repertoire. And then there was a phone call from Daniel Barenboim, saying he would like me to do Wotan in the new production at Bayreuth in 1988 with Harry Kupfer directing. My first reaction was no, I would sing Hunding and Hagen and Fafner. But he persisted and said, ‘We want to change direction and have a bass voice rather than a baritone for Wotan’. So I looked at a couple of scenes. I remember particularly the scene with the Valkyries in Die Walküre because that is notoriously high and difficult – the most challenging part of the role.

A baritone sometimes is lacking in weight and in the dark colour that the role needs. If you can sing the top notes well enough, a bass voice is great for the part of Wotan. It forced me to sing really well and brought on my singing immensely – it was very therapeutic for me!

The very first thing to do is work on your own, on the text, to translate it so you know exactly what’s going on. And you also work on what’s going on in the orchestra. You learn the notes, you learn the tune and you can do that quietly on the train when you’re commuting. Then I’ll go to a coach – David Syrus in this case, and Alistair Dawes.

It is important to make the part your own – if you listen to someone even two or three times you can start copying and you should be working from the black dots in the score. Ideally I’d listen to lots of people singing the role just once each – [Thomas] Stewart once, [Donald] McIntyre once, Hotter once. Ferdinand Frantz [a bass, and Furtwängler’s and Moralt’s Wotan in their 1950s Rings] is a great favourite of mine. He was forthright, he was economical, direct, a very Germanic, straight style – there was no artifice about it. I don’t like anything artistic that doesn’t come from inside, particularly in Wotan!

No part was ever so flushed out in detail. I mean, the Norns are still talking about Wotan in great detail in Götterdämmerung, and so do Waltraute and Alberich in that opera. The story of The Ring is the story of Wotan – from the moment he rips the branch off the World Ash Tree or takes out his eye to learn wisdom.

The length of Das Rheingold is two hours plus and you’re onstage most of the time – but there’s only 25 minutes of singing. However, you’ve got to be at the centre of the action, not just leaning on a pillar. But in Walküre you’re singing as soon as you come on and there’s an awful lot in the two hours you’re onstage. You have to prepare as if you were running a marathon. If I didn’t sing for four days before a Ring performance it wouldn’t be as good. Muscles get slack in a remarkably short time. You have to be singing every day. I would generally sing the whole of Wotan at home before a Ring performance. Interview by Mike Ashman

This article originally appeared in the May 2013 issue of Gramophone. To find out more about subscribing to Gramophone magazine and the Gramophone Reviews Database, please visit: gramophone.co.uk/subscribe