Saw this in my Youtube recommendations (not sure what this has to do with cats playing the piano) and thought it was an interesting idea.
We've all come across the computer musician or DJ who looks like they are checking their email while performing, but this really takes it to a new level.
Sorensen is generating the code that makes the music live in an improvisational session for this TEDxQUT talk.
It appears that he's using his own coding system: Impromptu to create this piece on the fly. It runs on OS X and is essentially a real-time DSP environment which allows for the creation of synthesis and graphics coding.
He describes it as such: " Impromptu is an OSX programming language and environment for composers, sound artists, VJ's and graphic artists with an interest in live or interactive programming. Impromptu is a Scheme language environment, a member of the Lisp family of languages. Impromptu is used by artist-programmers in livecoding performances around the globe."
You can see more of Andrew Sorensen's livecoding performances on Vimeo
I'm not sure if I would pay money to see this live, but its in interesting idea perhaps to perform via live streaming.