It was 29 October 1965 at Philadelphia's Academy of Music. The night was special in part because Nicolai Ghiaurov, a voice we had heard about more than had heard. The impact of his sound cannot be described and is barely captured on Byron's tape. Here's the playbill for that performance.
Conductor: Anton Guadagno
Mefistofele: Nicolai Ghiaurov
Faust:
Alfredo Kraus
Margherita: Ilva Ligabue
Elena: Mara Coleva
Wagner:
Gene Bullard
Marta: Charlotte Povia
Act I
Opening
Dai campi, dai prati
Act II
Opening
Su cammina
Ecco il
mondo
Act III
L'altra notte
La luna immobile