This Beardsley graphic says it all, I suppose... sometime maybe I'll get around to explaining in detail. Meanwhile, a few links to representative sites:
April 1999 at Horton Landing: notes to accompany a couple of tapes
University of Washington Ethnomusicology links
MandoZine, an online cultmag
Karl Signell Mediterranean musicians in the American diaspora, present & past
lyrics to several Agnes Bernelle songs