Another interesting modal tuning you can try is this C-modal: g-c-g-c-c. The 1st and 2nd string are tuned in unison. The 1st and 5th strings both act as drones as you pick out tunes on the 2nd, 3rd, and 4th strings. The tuning is very useful for songs which have, at various points, both the natural and the flatted 3rd and/or both the natural and the flatted 7th. Play, for example, John Henry. Darling Cory also works out well. I also like Kitty Alone this way, as the tuning carries echoes of the mountain dulcimer.

--- Steve