Here is a video of Glenn Gould (in 1964) playing (live) the Aria and Canons from Bach's Goldberg Variations; without repeats and performed as a continuous concert piece:
This is tough, intense, inspired music; and although I have listened to this piece hundreds of times over the past 39 years (various version by Gould and by many other interpreters), I haven't ever reached the bottom of it, or anything like - nor have I become fed-up with it.
As so often when Gould plays Bach, he shares the compositional credit in the sense that he recreates the music afresh (and differently from his album recordings). It is fascinating to watch him as he rocks his body and hums ('stimming' - for self-stimulating - as it is termed in Asperger's syndrome) yet without interfering with his hand control.
And look at those hands moving! They seem like weirdly shaped alien creatures; each pursuing its own independent agenda - and indeed each finger seems almost detached and autonomous of the hands.
The precision of playing is unsurpassed - and perhaps unequalled; and is especially evident in that Gould shapes each individual note, with as much attention to the note's ending as to its beginning - yet holds the musical idea with only the rarest and minor lapse in the sustained lines.
Gould's live playing is more accurate than any other great pianist I have ever seen; I only spotted one small actual mistake in the Aria and Canons (just about 9:50). Significantly, this is towards the end; and then there are a few mistakes in the separate Quodlibet - showing, I think, that Gould was becoming fatigued or losing the ecstatic state of concentration.
Gould is (in)famous for being the first great musician to eschew live performance - in his later career; and I think here we have the clues why. The way he played was so accurate, so exposed, and yet he made so remarkably few errors when playing well - that his standards were (even) higher than other greats, and even harder to maintain.
But such perfection was not attainable in live perfomance due to the need for sheer stamina: the exhausting travelling, setting up, socialising; the logistics of performance (new instruments, auditoria etc); the length of time he needed to play without a break. And Gould himself was so prone-to/ affected-by ailments and illnesses... That, in sum, I imagine it was excruciating for Gould (of all musicians) to be forced into playing suboptimally - to an external timescale; forced into 'faking it' for the audience.
Gould was subject to a great deal of ill-informed gossip (at least in the UK) about his technique - and some thought that he recorded exclusively because his pianism was faulty, and his playing needed to be patched-up by retakes and editing in order to pass muster.
In fact, almost the opposite was the case...