"You're twiddling and you find the tuning. Now the left hand has to learn where the chords are, because it's a whole new ballpark, right? So you're groping around, looking for where the chords are, using very simple shapes. Put it in a tuning and you've got four chords immediately— open, barre five, barre seven, and your higher octave, like half fingering on the 12th. Then you've got to find where your minors are and where the interesting colors are — that's the exciting part."
January 1, 1970
https://en.wikiquote.org/wiki/Joni_Mitchell