So, I'm an 11th grader that's been playing since 7th grade. I played principal in band last year (10th grade). Towards the end of the year I realized: As I go higher, my tone thins, I get quieter, I have not-so-good endurance, and I press. This was very clear as we were doing Holst's 1st Suite in Eb and while I did well, I was definitely working too hard. This became much more apparent when I had to play pieces such as Slavyanskaya by Kozhevnikov for All-County. I was principal in band really because the other good players had the volume, but not the focus, care, nor technique (Everything else). Now, November of 10th grade I got a really, really good teacher. He's an extremely knowledgeable, kind, insightful, and competent guy with a degree from Crane. He got me a 100 on my solo (Riisager Mvts 2 & 3) and I went to All-County on Tpt 1 (Last chair) (Didn't go for All-State). The issue of my tone and volume got pushed off to the side, worrying about the solo festival, and solos in concerts, and the music I got to play in a youth orchestra tour this summer. When we reconvened late August, I presented him with the issues, he tested me, and agreed that there was something wrong. His initial assumption was that I wasn't putting enough air through and was holding back. After some time and work involving lip slurs, mouthpiece work and such with a focus on really pushing air, getting a complete breath, and using it, not too much had changed. He knew there was some disconnect between the air being in me and then getting to the horn. The lips were ruled out. He had me borrow a baritone horn from the school. We both discovered that I play it pretty well. I got up to the high Bb and C on it with relative ease. D was tricky. Funnily enough, we agreed that on trumpet that E in the staff (High D for Baritone Horn) was where the problem really started. Next lesson, he had me take my mouthpiece and I blowed, starting on a thin concert Bb (Tpt C in staff). I slurred down to concert F (Tpt G in staff) and very quickly, I felt a rush of air and could feel the air going through properly and that concert F had a good buzz and a good amount of airflow. We transferred this to trumpet, and could easily tell that that Tpt G in the staff was getting all the air properly. As we moved up, on mouthpiece and trumpet, we noticed that even starting at C in the staff, there was less air. He made sure, as much as he could, that I was properly using my tongue and concluded I was. Tongue was ruled out. I put my hand on my neck and there was a definite difference between a concert F on the mouthpiece and a concert Bb on the mouthpiece. Same on trumpet. I was using my diaphragm/lungs/stomach/whateverYourPersonalTermIs correctly, tongue was fine, lips were fine, so we concluded: As I go higher, I'm trying to get the requisite air out to support the note, the tongue is trying to move into the right position, but as it does, the throat is closing, cutting off air, which makes me want to press to get the higher notes out because that circumvents the issue, which makes my lips tire out, which causes problems in the endurance department. My teacher, who has been reaching for over 40 years, thought about this again for the week, and couldn't figure out why this was happening, so we're trying to find a way to stop this from happening. I probably wrote several of the details in there COMPLETELY wrong so please don't analyze that thinking the answer is actually just an ignored elephant in the room. But the issue IS: As my tongue raises and air goes through, my throat is in some way tensing, stopping a portion of the air, not letting me support notes as I ascend. Even stranger and just more confusing: About two weeks ago, I started doing just a lot of lip slurs. A couple days later, the day before break starter, the problem just didn't happen. It didn't slowly improve over the days I was doing the slurs. It was suddenly, that day, not a problem. All the air I was putting in wasn't being stopped and I could feel the air just flowing. I played through a solo and it sounded damn beautiful. As I ascended things worked just great, my volume increased, I maintained support, and yeah, pedal tones were beautiful as usual as well. Played some of Messiah and I did our famous 16ths in the Hallelujah Chorus just perfectly, which under the the problem were quiet with poor tone (Don't worry, at the concert I was playing 2nd trumpet (and btw those jumps towards the end for 2nd are very annoying)). Unfortunately, over the next 4 days, the problem crept back and now I'm back in the same situation (Insert the underlined text from above). It's not like I overplayed, I kept relatively the same amount of playing each day, knowing that overplaying would probably destroy this beautiful playing. Nevertheless, the problem is back. So. None of my friends, educators, or colleagues know whats up. Do any of you know why this is happening (insert underlined text from above)? P.S. Sorry for writing the Odyssey hehe! P.P.S. Notice I don't say the throat closes, I'm aware that that's anatomically impossible. I think you understand what I mean.