I just discovered Dmitri Tymoczko's work on the topology of musical chords. George Hart did a wonderful ~7 minute video for the Simons Foundation about this idea. Prof. Dmitri Tymoczko (Princeton) "The Shape of Music" https://www.youtube.com/watch?v=XUyx31f-U3M Octaves in Modular Mobius Music - YouTube https://www.youtube.com/watch?v=Q8moAKBegFg http://www.brainmusic.org/EducationalActivitiesFolder/Tymoczko_chords2006.pd... http://dmitri.mycpanel.princeton.edu/voiceleading.pdf http://www.sciencemag.org/content/315/5810/330.3.full.pdf http://www.sciencemag.org/content/315/5810/330.2.full.pdf http://www.sciencemag.org/content/suppl/2006/07/07/313.5783.72.DC1/Tymoczko.... Dmitri's own web site with his actual program to play & display the chords: http://dmitri.tymoczko.com/ChordGeometries.html