For pop-rock and other styles of mainstream music there are massive libraries of chord progressions that analyse all the "hits" structure (or big picture). Thos

For pop-rock and other styles of mainstream music there are massive libraries of chord progressions that analyse all the "hits" structure (or big picture). Those would be really helpful with the "planning" layer... I.e: http://amitkohli.com/wp-content/uploads/2015/02/InteractiveChordProgression.html http://amitkohli.com/wp-content/uploads/2015/02/InteractiveC... I bet you can get results much more accurate feeding all those progressions as one of the reference layers.