[4lejandrito]

Thanks for the suggestion. I've been doing my research (sorry I have limited guitar knowledge, I am learning Spanish flamenco now).

According to https://en.wikipedia.org/wiki/List_of_guitar_tunings

You might be referring to:

Neil Young -> "B-F-B-E-G-B" or "D-A-D-G-B-D"

Joni Mitchel -> "D-A-D-F-A-D" or "G-G-D-G-B-D"

Which ones are the correct ones?

[sova]

All valid, different root chords for different songs.