A discussion of tunings in the old-time forum on the hangout reminded me of this tune. I'm tuned in A-modal with the 5th string lowered to G, making this actually in the key of G, assuming I'm tuned to pitch. The A part of this tune is played mostly out of a G-chord position (4th & 1st string at 3th fret, 3rd string at 2nd fret) and dropping down to a C-chord (4th & 1st string at 2nd fret). I learned this from Art Rosenbaum's LP and book.