This is terrific! Such a gift-thank you so much. I NEVER thought I'd be able to understand this stuff: I'm a musician, but tech terms including these were always casually bandied about by recording people who sin using them seemed to be speaking in a different and forbiddingly complex language, one so labyrinthian that I could never learn it. But thanks to your encouragement, now I feel I can. And the simple diagrams here are absolutely super: a really good aid accompanying your marvelous exposition. You are a really good teacher! Thanks again for your great description classes (with your prescription glasses ;+} )!