Test case: op. 111 1st mvt. Kovacevich comes down rather heavily on the top of the arpeggiated chord right at the beginning. It sounds mannered and messy; Beethoven wrote "cres" over it, not sforzato. In the Allegro, 26 seconds into Track 2, Beethoven writes "poco ritenente", but Kovacevich fails to adjust the repeated phrase, which now sounds clumsy, like a mistake by the composer. That's discouraging, so early in the piece. And details like this affect one's own responses. One gets a little anxious over what's coming next.
Others reviewers on this forum give us little beyond "I like it" for their 5 stars, leaving a reader in the lurch about what exactly is so great about them. This is my fourth album of the pianist's Beethoven. My feeling about Kovacevich is, on the contrary, that he is overly conscious of entering an immensely competitive field and somewhat unsure of himself. It never impairs the overall soundness of his readings, but nevertheless such irksome moments become irritants on repeated listening. A reviewer is obliged to notice these things and not rush to a review after one hearing.
Kovacevich's mastery is not in question, though it is scarcely the comprehensive "view from the peak" of such performers as Backhaus, Gilels or Pollini. His Opus 90, which does not pose huge interpretive problems, is well discharged. Opus 101 also offers a well-rounded perspective, although I would say he is hardly in the same league as the names I just mentioned. No more details now because I am just about to speak of a feature of this album that redeems everything, and which I have left to last for this reason.
You will note that I have not said a word about the Arietta of Opus 111. But after all the doubts I have expressed, you and I would both expect that more of the same critical comments must follow. However, things change in this last track of the album.
When the stormy clamour of the first movement subsides, something quite extraordinary unfolds in this performance. From the moment that the first 3 notes sound, you are enveloped in an atmosphere which I can only describe as utterly enchanted: and what follows is a spiritual argosy so evocative that one's critical faculties are calmly put out of action to surrender to the magic of a profound and emotionally transporting musical meditation. The savagery of the central "boogie woogie" section is all the more terrifying, the balm of consolation which ends proceedings all the more affecting because in these 17-odd minutes Kovacevich seems at last to have found a way to tap his inner resources that longed for an outlet through this music.
I think it would be shameful to cry out "the greatest". This kind of music making does not need silly apostrophes of this sort. All the same, comparisons are revealing, if you now go back to other interpretations that seemed "deep" on previous hearings. E.g. Barenboim sounds positively ponderous now, and prosaically literal, as if he was feeling his way into a terrain he had never traversed before; also the treble of his piano has a biting clangy sound. Literalness is also a word that seems apt for Oppitz, who approaches the movement in a cool, detached manner, as if he was wishing to avoid depths that maybe he can't handle (that was also Kempff's way with this music, and Oppitz studied with him). The closest approach to the kind of magic Kovacevich evokes is struck by Eschenbach, although the feel and temper here is almost as if an ineffable pain afflicted his soul and seeks redemption in extremely slow, prayerful utterance (his reading takes 22 minutes!). Pollini's account is "difficult" to place here because of his truly classical mastery. When you live with it for years, you begin to understand the reticence, the desire to let the composer speak without deliberate searching; and similar considerations apply to Backhaus. I mention these two only because they represent the top of the bracket for the whole century; and the whole point of this highly selective comparison is to stress just how exceptional a place Kovacevich's reading of the Arietta may claim in this roster.
What is my conclusion and recommendation at the end? Very simply this: you must buy this album for the Arietta. Even if you feel that my criticisms are fair and just, this movements wipes them away. I would not normally recommend buying a whole album for half a sonata. But this is so exceptional a reading that it is worth the price of admission. Despite 50 years of collecting, I've come across rare issues like this less often than I can count on the fingers of my hands. And on those occasions, accept what is given and maintain silence over what is lacking.