That would be the second movement of Beethoven’s piano sonata Opus 111 — the final movement of his 32nd and final piano sonata.  Here is what a couple of pianists say about it:

 The pianist Robert Taub has called it “a work of unmatched drama and transcendence … the triumph of order over chaos, of optimism over anguish.” Alfred Brendel commented of the second movement that “what is to be expressed here is distilled experience” and “perhaps nowhere else in piano literature does mystical experience feel so immediately close at hand”.

Andras Schiff, in his lectures on the Beethoven piano sonatas, finally runs out of words (acceptance, forgiveness) to describe the last few minutes of the sonata, and can only play the music.  At some point after the first few variations in the final movement, the music takes off into another realm of spirit and meaning, leaving language behind.

Perhaps the most moving piano recital I ever attended was Rudolf Serkin late in life playing Beethoven’s Opus 109, 110, and 111 at Symphony Hall.  He played the 111 after the intermission, and that was it.  No encores.  Just 25 or so minutes of music — after the arietta, there was nothing left to say.

Here is Claudio Arrau playing the sonata in Bonn in 1977, when he was over 70.  Looks like the air conditioning was broken, because the sweat pours off him.  No matter.  I heard Arrau play about a decade later, and he was moving so slowly I thought he’d never make it to the piano.  His tempi were also slow, but he made them work.

Here we are on the 50th anniversary of Kennedy’s assassination — a time for funeral marches. But at some point you have to get past the funeral marches — and Opus 111 is where you need to go — the triumph of optimism over anguish.