OK- I'm not very technical so I know nothing about resonance or frequencies and all that Jazz (pun intended). From the discussions I've read, the current standard, at least in the U.S., is high pitch at A=440 hz, where it used to be low pitch at A=432 hz. This actually tells me.... nothing. However, I think I may have figured it out from the various things I've read, and I'd like to know if I have the basic gist of it. From reading about needing to shorten the slides slightly, or the bell tail, or modifying a LP trumpet by shortening some part of it to make it HP, then I'm supposing that Low Pitch vs High Pitch would simply be just a technical term for saying that if you put an LP horn next to an HP horn, and both played perfectly in tune within their own pitch, then the LP horn would actually be playing flat when compared to todays HP standard. Am I correct in this guess? If so, what would be the difference in pitch? Would a Bb in LP just sound like an overly flat HP Bb, or would there be actual note differences, such as an LP Bb sounding like an HP A natural or something else? I hope I'm not being too confusing with the way I put all this, but I'm just trying to figure it out in layman's terms vs technical terms. If I dont have this correct, could someone please explain it to me in terms that a non-technical mind like mine can understand? Thanks for any help.