That has been done indeed, that state transition diagram: see http://mugglinworks.com/chordmaps/genmap.htm http://mugglinworks.com/chordmaps/genmap.htm for a ge

That has been done indeed, that state transition diagram: see http://mugglinworks.com/chordmaps/genmap.htm http://mugglinworks.com/chordmaps/genmap.htm for a generic chord progression map.