This list is just a convenient collection for my current research, but you may find the lectures interesting/useful.
I'll add links as time goes on.
BBC Documentary Archive "Abstract Artists in Their Own Words" https://www.youtube.com/watch?v=3A2Fk4xnXI0 or (if you're in the UK http://www.bbc.co.uk/programmes/b04gvb86)
Brian Eno "BBC Music John Pell Lecture 2015" a BBC podcast at http://www.bbc.co.uk/programmes/p033smwp
Bill Viola "The movement in the Moving Image" UC Berkeley (2010) video on YouTube at https://www.youtube.com/watch?v=t0RCkNugozU
"In The Ocean - A Film About The Classical Avant Garde" https://www.youtube.com/watch?v=h0NwiTHIhGM
Prof. Christian Wolff lecture: Experimental Music - lecture 9 in this School of Advanced Study, University of London list http://apple.co/1LgxClK #iTunes
Steve Reich - "A New Musical Language" in 6 parts, included in this list on YouTube https://www.youtube.com/playlist?list=PLstclZNr4-uVO7lISoR_w5dy4mzVMc-z6