Integral types of musical periods and subcultures/genres.
Two things: it's probably possible to assign integral types to historical periods of music. e.g. Baroque and Ti or Romantic and SF.
With contemporary music, due to the huge variety of genres, sub-genres and fusions catering to every kind of demographic, and the lack of any kind of overarching social movement influencing musical creativity, it's probably only possible to type individual genres and scenes.
So, let's hear your opinions people. Music is something I love, and classifying things is as well. I'd love to do both in this thread.
I might have some more unrelated thoughts if I develop them later.