I like this thread, and will use it for reference. But I believe there are also five-tone modes, which are interesting. I lived in Japan when I was a kid, and find that a number of old Southern Apalachian songs sound Japanese, because they appear to use the same notes. I am not trained in musical theory, but I believe Little Carpenter is in a mode like the more accessible and familiar Japanese songs like the Coal Miner's Dance (Tanko Bushi) or China Night. If I wanted to play these on a guitar, I would use one chord and when it seemed right to change chords, add a second to the chord instead. Most Chinese songs have a simliar sound, so I would guess the mode is the same.

More typical Japanese songs have a wilder sound and are less accessible to Western ears. These appear to be in the same mode as Shady Grove, and possibly Oh Death (as Dock Boggs sings it) although I haven't looked at that one so closely. And in the improbable event anyone wanted to play these on a guitar, it would go with D (Tonic) and C [Leading ???] chords. Or some folks might play D and A minor. A long time ago, I believed I had the scales worked out, but forgot how they went.

Does anyone either (a) know the theory for Asian music or (b) think this is worth pursuing.