Trumpet Master Classes from the Editors of Windplayer Magazine
One of the problems I've notices in a lot of trumpet players who are trying to develop the upper register is that they have a great deal of tension in their breath. This comes through as a strained sound which usually makes the pitch go sharp and it can cause a lot of tension in your throat and tongue. I recommend playing long tones, being very aware of your sound and taking breaths deep and low in your body. This means the shoulders don't rise and any rising of the chest is a result of the lungs inflating, not muscles lifting or muscular tension in the chest.
I have students focus on tone and taking a deep relaxed breath, then focusing in on the sound and making it relaxed and full. Imagery drills are very good, too. The book The Art of Breathing, by Nancy Zi, has approximately 40 drills witch take your mind away from the physical involvement of breathing.
I also think it's important to use the vowel position "Ah" through every register. Some books recommend using"Ah-ee" to arch the tongue and get the notes out in the upper register but you end up with a thin uper register and intonation problems, especially sharpness in the upper register. Because of this, I disagree with using the vowel syllables to arch the tongue and increase your range as and aid to the upper register.
Mouthpiece selection is also important. A lot of trumpeters like to use "pea-shooter" mouthpieces to get high notes out. The sacrifice sound and flexibility, everything except high notes. I like a bach 3C mouthpiece, right off the shelf. I'll switch the mouthpiece if I need to change the tone a little. my 3C is a brighter mouthpiece than my 3B, but the 3B has a gusty, full sound for strong orchestral playing, and also has a nice full tone for playing a little darker when needed. Mouthpiece placement should be exactly the same in each register. My mouthpiece is in the same place for a pedal C as it is for a double C.
Hitting high notes consistently has a lot to do with practicing. To play high trumpet and keep the flexibility to do other kinds of playing, which is necessary for studio work, you have to practice. I put in a minimum of three hours a day. A practice routine for a student trying to develop high chops would differ for each individual. For a basic routine, though, I'd do a fair amount of Herbert L. Clarke studies and Max Schlossberg's drills. I also use Charles Colin's lip flexibility studies, a lot of St. Jacome, and others.
In your practicing, be sure to include some lyrical studies, such as Charlier etudes, to concentrate on phrasing and tone production. It's not as important to do a lot of technical etudes as it is to get in some lyrical studies.
Some players have endurance problems. That can be due mostly to tension in your breathing, which makes it more strenuous on the face. When you're trying to get the notes out and the air's not relaxed, your embouchure and other parts of your body start compensating for the inadequacies. Relaxed breathing helps endurance. There's still tension and support, but in the right places. You can't have it in the upper part of your body.
Minor embouchure problems can also cause endurance problems. My embouchure doesn't change for each register. The corners should remain anchored, and the center of the lips should always be flexible, without tension.
The strength and endurance comes from the corners back into your cheeks, which have bulkier longer facial muscles. The fine muscles in the front of your embouchure can't take the stress of a lot of strenuous playing. Once you set the embouchure correctly, the muscles in front have the opportunity to relax enough to perform. Some people have a lot of tension in the front of the embouchure, and are always thinking about the size of their aperture. This focus shouldn't be on the mouthpiece, but on their own lips.