Another cornet newbie question from a former string player! What do you call the adapter(?) thingy between the mouthpiece and leadpipe on an old cornet? I picked up a cheap old York for my kid to play (or for me to play with, although I don't play...) and this bit is pretty trashed although the rest of the cornet is decent. If the piece is just for playing in A, no problem. But do I need it for Bb? (I do have the HP and LP tuning slides so I'm good there.) After I washed and lubed it and stuck the MP in without the thingy, the kid played me a scale that was beautifully in tune (with itself), put it down, said it was easier to play than the student horn, and walked off to play video games. I won't be turning my elementary school band student loose with this cornet anytime soon. Too pretty. But I want it functional! Please...tell me what that thing is called! Thanks!!