I agree with 100% Michael on the jazz.

For myself NOTHING is original, it is all theme and variations and the theme is stolen.

It is the hybreds - that appear to be original - but they are shadows of their genetic roots.

When I have backed up from my current Renaissance research (a weekend will stretch into probably several years thanks to Bruce's page) , I have no doubt that elements of some very unusual "modals" (to my own current ear)will find their way into improvisations and be considered "original." They won't be..... they are only ghosts of the past revived in a modern setting.