http://www.smithsonianmag.com/arts-culture/5-12-examples-of-experimental-music-notation-92223646/
https://www.theguardian.com/music/2013/oct/07/graphic-music-scores-playing-pictures-tom-phillips
http://opinionator.blogs.nytimes.com/2011/08/03/scoring-outside-the-lines/?_r=0