Goodness knows what cold virus was haunting the cobbled back alleys of Vienna that December in 1976 - or was it just a collective case of mass pig ignorance? - but I have never heard such a gratuitously inattentive and inconsiderate audience hack its way through an entire performance almost without respite - it's absolutely maddening. I expect to be tolerant of some audience noise but this is ridiculous.
My disappointment is compounded by the fact that contrary to my hopes and expectations, Nilsson and Vickers do not here constitute the dream-team partnership we might have envisaged. Despite the amplitude of her voice and her continued ability to hit the top notes, Nilsson is clearly labouring as she lows and heaves her way unsteadily through the part, quite without the ease and gleam we hear in earlier recordings from the 60's and early 70's; at times it is almost painful. The Brangäne is harsh and wobbly and rather ordinary; the Kurwenal similarly competent but unmemorable. It is a surprise to hear the inimitable tones of veteran tenor Anton Dermota as the Sailor here at 66 years old and still singing well and the equally unmistakable tenor of Gerhard Stolze is a characterful asset as the Shepherd. The noble sonority of Hans Sotin's rich bass lends pathos, dignity and gravitas to King Mark's lament.
Vickers, too is below par; perhaps it is fair to say that both principal singers are here past their legendary best, although Vickers is here only 50 while Nilsson is already 58. His tone is often hoarse, grey and lacking centre; he frequently lapses into his besetting fault of crooning.
Horst Stein was an excellent conductor and often paces matters aptly without generating much excitement; there is a certain slackness where we need more dramatic tension but the prelude is replete with yearning (insofar as you can ignore the relentless hacking) famous, the climax to Act 1 exciting, and the extended love duet in Act 2 goes well, with Vickers using a tender mezza voce.
The mono sound is quite distant; voices are often too recessed but not too damagingly so. It's perfectly acceptable for a live recording of that provenance but nothing special.
So unfortunately this is not the collector's item all "Tristan" obsessives will have been searching for.