WOW! great question I'd like to hear more about the tri tone also. any recommeded reading on these subjects?

thanks audiokid, I've posted a reponse to the question.

Riconga: Although I remember a fair bit from my music history classes at conservetoire it's been quite a few years and it's getting a bit sketchy! The kind of "Encyclopedia Brittanica" that we all used for music was the Grove, beyond that I can't specifically remember individual books.

Greg