I heard it live and he actually messed up at one point and had to start the piece again.
I can't fathom the concentration it takes to play some of the longer pieces off of Einstein etc. Let alone something like Reich's Piano Phase. Superhuman focus...
I often wonder though -- if Glass (or Reich for that matter) happened to start their careers at a time and place where sequencing and sampling were commonplace and accepted, and created their work using that medium, would the music really suffer much? Is the superhuman virtuoso musical dexterity and focus required to properly perform these pieces really germane to their success as musical compositions?
During the period AFTER the advent of sampling/sequencing but BEFORE the rise of YouTube as a channel to consume music you might have been right.
But I think people view music performance now much more than they ever viewed music performance prior and witnesses the actual act of performing is intrinsic to enjoying many pieces.
It's one thing simply knowing a piece was played by humans but seeing it played adds an extra dimension and I think the popularity of some performances now depends on this.
I can't fathom the concentration it takes to play some of the longer pieces off of Einstein etc. Let alone something like Reich's Piano Phase. Superhuman focus...