For more than 50 years the Ring recorded by Decca at Bayreuth in 1955 has lain unheard in the company’s archives, in spite of the fact that the Holländer of that year was issued at the time. On the strength of this first instalment it is just as valuable as the gold Fafner guards. The history of its suppression by John Culshaw (who disliked live recordings) and the machinations of EMI’s Walter Legge (who claimed exclusivity over Hotter and Varnay), and the other vicissitudes that prevented its earlier issue, are chronicled in Mike Ashman’s fully researched notes in the accompanying booklet, which has vivid photos of the production. It is a sad tale he has to tell but – thanks to Stewart Brown and his team’s labours at Testament – it has a happy ending.

Of course, in one form or another the Bayreuth Ring cycles of the 1950s, in Wieland Wagner’s groundbreaking production now acknowledged all round as probably the most compelling in the work’s history, have been made available on official and unofficial labels over the years; but none of those – with their many merits – has anything like the sound-quality achieved here. The placing of the microphones was inevitably limited, but with Kenneth Wilkinson, Gordon Parry and Roy Wallace in charge of the engineering, the results are arresting in warmth, immediacy and range, catching in exciting manner the peculiarly fine acoustics on the Green Hill. Time and again, as I listened enraptured to this overwhelming performance, I felt as though I was sitting in the Bayreuth stalls.

At the time, Keilberth never seemed to receive his due but here – as in other operas with him in charge recently unearthed – his command of every aspect of this vast score is unerring in balance, detail and overall Schwung. In that, it rivals Clemens Krauss’s legendary 1953 reading and is quite as exciting as (and better sung than) the 1966/67 Böhm set, until now the first stereo recording from Bayreuth. It has been said that in 1955 Keilberth’s interpretation reached its peak of achievement; on the strength of just this one opera I would confirm that verdict. Besides in 1955, four years after its birth, the production and the ensemble reached their zenith.

No opera house or recording has since rivalled the cast assembled here, not even the Decca set, by which time Hotter, Windgassen and Neidlinger were all some 10 years older. In 1955 all three are at the peak of their form and – singing live rather than in the studio – are that much more involved and involving. Listen to the meeting of the titans, Alberich and Wanderer, at the start of Act 2, and you will hear just how the two most authoritative interpreters ever of those roles match up to each other in vocal command and verbal acuity, superbly supported by Keilberth and his dedicated orchestra. Listen to Windgassen, so poetic and musically exact, line and tone in perfect accord, in the so-called ‘Forest Murmurs’, then his sense of loneliness and wonder as he reaches the mountain-top in Act 3. Having awakened Brünnhilde, he still has the stamina to partner an inspired Astrid Varnay in an elating account of their love duet, with Keilberth stirring his orchestra into new realms of ecstatic playing.

All this is at the cutting edge of Wagnerian interpretation. If you add to it Paul Kuén’s experienced and nasty but never exaggerated Mime (so puzzled and equivocal in his Act 1 encounter with Hotter’s magisterial Wanderer), Maria von Ilosvay’s properly mysterious Erda and Josef Greindl’s deep-throated Fafner, you have a cast to dream about. Don’t take my word for it: buy the discs and experience Wagner as he was supremely performed in those special days, and thank your lucky stars someone has had the persistence to unearth the recording. As Peter Andry, the producer of the recording, says in his introductory note: ’It is as if a much-treasured and irreplaceable family heirloom, feared lost for ever, has suddenly reappeared thanks to the unexpected care and generosity of some beneficent, distant relative.’