I've been playing a Bach Strad 184G large bore cornet for a number of years now. It's a great little horn, but the top line F has always been extremely sharp. Since it has a trigger on the 1st valve slide, I've just gotten into the habit or throwing it out about a half inch to bring the note down. It happens with any mouthpiece, BTW - various size Bachs, Wick, Stork, etc. Well, last Friday, I put an old Mt. Vernon main water key on it, to match the MV water key I had installed on the 3rd valve slide a number of months ago (I bought an old MV cornet leadpipe on eBay about a year ago for parts - that's where I got the two water keys). Now, for the 3rd slide, the tech obviously installed the whole works, but for the main key, I just switched out the lever, copper-colored spring, and brass screw (the modern screw is nickel), and put a black neoprene "cork" on to match the 3rd valve one. Anyway, I played it a little to make sure the key wasn't leaking, and I thought, "that F sure sounded more in tune". I played a little more, and then took out the tuner and checked it - the F was practically in tune, just barely sharp on the meter. I've played it in two rehearsals this week and no trigger is needed! What happened??? I first thought that I had possibly corrected a leak, even though the old key seemed to seal fine with no leaky feel or water drips. The original spring was much stronger than the old MV one I put on, too. To test the theory, I tried playing the F with the water key slightly to fully open; no difference in tuning (little difference in tone, either). So, what do y'all think caused it? Mt. Vernon magic? Weaker spring? Brass screw? Different water key? Brain aneurysm? I'm pleasantly surprised, but have no explanation for the change.