Seeing a clip of her doing the end of the Immolation scene from the commercially released Chereau production, which the BBC saw fit to include in a brilliant documentary about divas, converted me to opera on the spot. Over the years I have explored every utterance of hers that is available and I think this Immolation scene, from her first complete Ring (Bayreuth, 1975) is perhaps the best, at least vocally.

Maybe for some this will already sound over-ripe, but for me this is Wagner singing at its greatest – the voice is rich, full and secure in all registers, there is beauty and warmth in the timbre, and she can do every phrase exactly how she’d like to with no compromises. I don’t know that anyone else ever had every single one of these attributes come together in such a gratifying way, and of course Dame Gwyneth herself couldn’t sustain it at such a level for very many seasons – by the time of the commercial release of the Chereau the middle is hollower, the top is slightly thinner, and the vibrato is crossing the line towards a wobble. So I particularly love this performance as a document of a real sweet spot in her singing, where she was truly great, bringing the stunning timbre and facility from her youthful Verdi singing to the beginnings of her Hochdrammatische days.