I respectfully disagree...I have a Shilke 6A4A and after a few minutes of playing notes on it above C, I begin to really scream ...me, not the horn. Then I remove my crooked lower central incisor from the back of my lower lip, and start playing again with my regular mouthpiece. Oh, I get it. you're talking about the trumpet screaming, not the owner... Seriously, I fully agree with practice being the only way to get there. After one full year as a comeback player, I can finally claim an E above the staff. What this does for me is firmly solidify the C above the staff, the top of the range for most compositions. I spend most of my practice time ensuring my tone is smooth, playing long pianissimo notes for breathing control to create consistency of tone and volume, also lip slurs, and partials. I do have very crooked lower teeth (natural bubba teeth) and I have to keep pressure on my mouthpiece at a minimum to ensure endurance, and follow my mentor's advice of "more meat in the mouthpiece" to develop range while minimizing pressure. The range truly seems to have come along as a by-product of hours of practice. Practice, practice, practice!!!