Last thought

I could not go to bed without figuring out why odd partials are bright and evens are warm. I think I got it. Even partials have a more direct relationship to the fundamental frequency of the string, that is the note. So: string's fundamental frequency is, say, low E. What's the second partial? Well, the second partial vibrates at exactly what you induce when you clamp off half the string by putting your finger on the twelfth fret and get the fundamental frequency of that: an E that is a whole octave higher. And what happens when you clamp off another quarter of that string? You got it. (Sixth partial is a B, eighth is E, etc.) So the evens, on the whole, add up to the same note.

But what about the odd partials? Third partial is three times the frequency. That is, about a B. And if you know your E major scale off the top of your head, which I do not because I have the musical theory of a flea, you know that B is the fifth. Fifth partial? G#, otherwise known as the third. Mostly harmonizing.

Now, why we call those bright, and the evens warm, that's one of those weird synaesthetic things, I assume. OR ELSE it's sloppy terminology coming from the pickup world in which one pickup tends to get both the higher and the odds and the other gets the lower and even, because it makes more sense to me just to say all higher partials are brighter (of course, higher notes) and lower partials are warmer. I'd favor a term like "rougher" for odds. And then we get into the term I've heard with pickups, "fatter"... Good night!