I consider the modal names for duclimer tunings to be misleading. In so-called "mixolydian" tuning it is rather difficult to play any tune in the mixolydian mode, such as Orientis Partibus that drops to the tone below the tonic. In addition, one can play in different modes with the same tuning, especially if one is willing to use a capo, and a 6 1/2 fret is present. Dorian melodies can easily be played on the melody string in the so-called "Aeolean" D-A-C tuning, if a 6-1/2 fret is available.

Hence I prefer referring to the tunings by such designations as "D-A-D" or "1-5-8".

As far as I have seen, the most popular tuning on the east coast and in the southern plains is D-A-D. I don't know about the Pacific Northwest. The D-A-A tuning is often used for teaching beginners, and I get the impression that it has been unfairly stigmatized as a novice-tuning for this reason.

T.