My interpretation (loosly) of say the difference between classical (old) and folk (old) is that Folk music was passed on oraly and in that process evolved and changed. Classical music was written down, thence becoming fixed as written or scored. Currently, I am involved in a folk art--quilting--in which I see technics being handed on and changed before my eyes and evolving constantly. Also ideas being exchanged but not written down or recorded in any way. Also adapting and exchanging of ideas constantly. However the original purpose being retained.
Well that's in my experience anyway!!
L