To that list we can add Toulouse Engelhardt, based on his recent solo album Mind Gardens (Lost Grove Arts 1008). "13 Novelties of Space, Time and Contemplation" is how the album cover describes the music. It fits. Other than one duet for guitar and alto flute this is an all-solo affair.
Toulouse plays six- and twelve-string guitar with the sort of flourish one expects of someone worthy of such lengthy display. I like the way he voices chords especially. He gets some beautiful, bright, resonant sounds by doing such things and it is great to hear. He can also pick out very well on chords-melodies in interesting ways that may remind a bit of Kottke but as an extension, not a copy.
It is music that washes over you in most pleasing ways, yet for the guitar conscious he is doing something that's worth attending to. Check out his nice version of the Shaker hymn "'Tis A Gift to Be Simple" if you want to hear his very creative way with something familiar.
This is good. Very, very good. Acousticians take note!