OK...as an engineer I'll admit that I tend to get a little "geeky" about the physics of things from time to time. Anyway...I found a reference to this website "elsewhere" and I thought I'd share it here. Be happy to discuss the contents with those who have read it and "understand" (or even "think" they understand) what's being said. http://joeleymard.free.fr/Benade/Trumpet73/Trumpet73.htm At the same time, here is a second site that provides some basic information on the creation and sustenance of sound waves within brass tubing. You might be wise to read this one through before the one mentioned above: http://hyperphysics.phy-astr.gsu.edu/hbase/music/brass.html#c1 One last site which perhaps says similar things in different words is that of Nick Drozdoff (whom I've made mention of before). Nick is a physics teacher who spent a stint playing with the MF band so he's got an "eyeball" on the situation from two sides at once. Check out: http://www.geocities.com/Vienna/3941/ So if you've got trouble falling asleep at night...print these sites up and use them for bed-time reading!