Joni Mitchell on composing in alternate tunings, 1996

"If you’re only working off what you know, then you can’t grow. It’s only through error that discovery is made, and in order to discover you have to set up some sort of situation with a random element, a strange attractor, using contemporary physics terms. The more I can surprise myself, the more I’ll stay in this business, and the twiddling of the notes is one way to keep the pilgrimage going. You’re constantly pulling the rug out from under yourself, so you don’t get a chance to settle into any kind of formula."

From the book Rock Troubadours.