While the mono sound on this issue isn’t the best, it’s perfectly listenable and one soon forgets the hiss and distortion once one is drawn into the stellar characterisations by four artists all in their prime.
I still would not dispense with the 1960 studio recording in favour of this, as Callas’ singing there is almost as good technically despite some flap in the top notes and there are many compensating subtleties of inflection plus the advantages of excellent stereo sound, Corelli’s thrilling Pollione, Ludwig’s glamorous Adalgisa, the same sonorous Oroveso from Zaccaria and experienced, sympathetic direction from Serafin.
Similarly, I very much enjoy the live RAI broadcast (from the same year as this Milan performance, also with Del Monaco in sterling form and directed by Serafin) which is in marginally clearer, cleaner sound.
So, I’m greedy; I want to have all three and find different virtues in them all.
Having said that, this performance probably enshrines the best of all Callas’ many assumptions of this role and Simionato’s Adalgisa, in particular, is a performance to treasure.
Del Monaco is a real helden-Pollione but not brutal or insensitive, nor necessarily inferior to Corelli’s equally virile Roman in the studio recording.
Votto is a relaxed, pliant accompanist, reluctant to impose himself upon four such experienced and musical soloists (and the supporting roles are well taken, too).
In the end, there’s no complete recorded performance - not Sutherland, not Caballe, good as they are - to touch Callas’, and you must have one or two of the three under discussion here. (The first Cetra Callas ˝Norma˝ sees her partnered by indifferent singers and she has yet to deepen her characterisation.)