I recently did some intensive comparative listening to the dozen or so "Aida" recordings I own and came to a startling conclusion: despite it having been recorded complete scores of times, only two or three "Aida" recordings really pierce the heart of this most venerable of war-horses, and chief amongst them are the famous Muti version (see my review) and this one - now available absurdly cheaply on Regis - a bit hissy and rumbly but in vivid, immediate mono. OK, Callas's top C in "O patria mia" wobbles a bit but otherwise no other soprano begins to inflect the text with the degree of subtlety and pathos she achieves. And when Gobbi joins her, we are listening to a master class on how to enact Ghislanzoni's text; Gobbi makes fellow baritones sound merely bland and workaday - especially Cappuccilli in the otherwise striking Muti set. In addition, both have such recognisable and intense vocal personalities, Gobbi with that inimitable, Italianate "bite" and flickering vibrato, Callas with her melting portamenti and sudden, powerful surges.
Barbieri is a tower of strength in a role made for her and Tucker, while not the subtlest of tenors is rock-steady and heroic of tone; certainly few tenors have his vocal capability in this cruelly taxing role - only Del Monaco and the young Corelli in the 1956 Cetra recording capably conducted by Questa provided more thrills. Ultimately my favourite "Aida" remains the Muti set in excellent stereo sound with Caballe in infinitely tender, caressing voice, Domingo golden of tone and very expressive in the best of his three studio recordings, and Cossotto displaying simply jaw-dropping intensity as Amneris but this 1955 recording, which benefits from Serafin's readiness to sacrifice the metronome to dramatic exigency, will always be amongst my favourites.
