The next canon—Variation 6—crystallizes some important differences between the two sets generally. In Gould I, the imitative sequences in the two top voices are played with winsome, wistful sweetness, a romantic yearning held in check by baroque tact. Gould II is dryer, more objective, easier to admire than love.
The minor-key variations are another useful basis of comparison. Consider the 25th variation, a piece of such complex chromatic side-slipping that the harmonic language seems poised on the verge of incoherence without ever falling over. Gould I plays it like something from the late romantic period. (Gould himself later disparagingly adduced Chopin, although to me it's more evocative of Wagner.) Gould II eschews any overt interpretative stance at all, simply plays it cleanly, letting the music speak for itself. I suspect opinions on these two choices will be contentious, but I find them equally valid and equally satisfying.
Peter F. Ostwald's book about Gould tells us that by the end of his life the pianist was a physical wreck, with many muscular and skeletal problems impeding his ability to perform. I don't question it, but neither do I hear any evidence of it in his second recording of the Goldbergs. I do hear something else, though. I hear a brilliant musician who has become so reclusive, so sealed off from and frightened by human connection that he makes interpretive choices that stubbornly eschew sensuous appeal. An ascetic who would rather risk repelling listeners than risk inviting them in. A thinker who writes both sides of an interview because he can't bear to subject himself to questioning, even when it's sympathetic questioning from a knowledgeable admirer. The personal tragedy of Glenn Gould's last years is embedded in this performance, encoded in every bar.
Nevertheless, the set is inarguable evidence of Gould's greatness, as much so as its predecessor, and deserves a place on the shelf of every music-lover. The earlier performance certainly strikes me as more human and more humanly lovable, and of the two, it's the performance to which I shall more frequently return. But Sony has performed a service by putting both sets in one elegantly produced box and letting us judge for ourselves.