This second instalment of the second Bayreuth Festival Ring cycle from 1955 is unlikely to change the views of those for whom a particular strength of the first cycle (released by Testament a couple of years back) was Astrid Varnay’s Brünnhilde. Wagner’s writing in Walküre suits Martha Mödl’s voice better than it does in Götterdämmerung (1/10) but you have only to sample the brief passage early in Act 3 where the two singers go head to head to appreciate the difference.

As for Act 1: if you like your Sieglinde to be more vulnerable than fiery, then Varnay might lack something. But the golden gleam of her voice is so expressive in the role’s lyric flights that vulnerability seems a very optional extra. Ramon Vinay doesn’t do vulnerable either, and there’s little of the “gentle ecstasy” Wagner asked for in “Winterstürme”. But Vinay never sinks into unmusical hectoring, and his sustained power in Act 2 as well as Act 1 is highly impressive. The big moments in this performance also offer some vintage Hotter. Occasionally he sounds as if he might have been on autopilot – perhaps it was a hot night in the Festspielhaus – but in the raging torment of the Act 2 narration and the sorrowful determination of Act 3’s Farewell he is supreme.

As before, Decca’s pioneering stereo sound can downgrade the orchestra – especially the woodwind – to bit-players, and Keilberth’s tendency to rush through transitions remains an irritant, even if one welcomes the corresponding reluctance to overweightedness and excessive lingering. One positive result of the brisk tempi is that there is room on the fourth CD for fascinating snippets from 1955’s Tannhäuser, also conducted by Keilberth, after Igor Markevitch jumped ship at a late stage.

As Mike Ashman’s notes explain, Keilberth didn’t approve of Wieland Wagner’s insistence on following the Dresden version of the opera’s Overture with the post-Tristan Paris version of scene 1: but that didn’t prevent him leading a dazzling account of the Bacchanale. The short vocal extracts from Act 3 are fascinating, too. For some reason Fischer-Dieskau’s riveting yet distinctly mannered performance of the “Evening Star” song is missing its first pair of words (“Wie Todesahnung”), and the ensuing extract from scene 3 stops in mid-phrase. Nevertheless, there is enough here to show how forcefully acted as well as powerfully sung the exchanges between Fischer-Dieskau and Windgassen were.