Graph layouts use spring layout algorithms. Springs and other physical systems are very interesting systems and have fundamentally musical properties such as decay and oscillation.
I took the graph drawer found here and stole the state of the graph every couple of frames: http://js1k.com/demo/618
The instrument I used in the background is an additive string I modified from here: http://csoundblog.com/2010/03/bowed-string-additive-synth/
This is a web based UI being rendered by csound: http://csounds.com/
The source code for the whole shebang is at http://github.com/abramhindle/mongrel2-musical-relay http://www.youtube.com/watch?v=JN17PkR63I4