>>Here's a question which I was originally going to post privately to >>Chalmers,I've read about them for >>many years, and all of a sudden I realized that I don't know the >>fundamental reason behind their origin. Any thoughts are surely >>appreciated....thanks...Hstick
Neil: - I was waiting for John's succinct response myself, but I'll throw in that tetras operate as three-interval sets below an initial tone. Then began being joined as pairs, with a 'diazeuksis' separating, ending up with octave closure. That's how I think of tetrachords. John's articles and book are much more informed. Joscelyn Godwin also expresses their origins and simplicity very well in "harmonies of heaven and earth"