I can't seem to find any information about this, probably because "half-vavling" isn't the proper term. The effect I'm talking about is when you do not depress a valve completely and play into your horn. To create this effect properly, do you hold down all 3 valves? How do you control what pitch you create? If I wanted to half valve a G (in the key of Bb) how would I do it? What about half valving an A? Thanks.