Reply To: Beginning Band Trumpets
When students are having issues like these, sometimes taking a few steps back is helpful. In my experience, always beginning class with just the mouthpiece is helpful; after all, the size of the mouthpiece appears to be a theme when it comes to beginning high brass. if students can experiment with holding the mouthpiece exclusively with their thumb and pointer-finger, at the natural angle for their embouchure (usually slightly downward) the students will be able to focus on getting a healthy tone from something much simpler and less things to hold onto. Only using the thumb and pointer-finger is important because using all five fingers can result in pushing the mouthpiece onto the embouchure too hard which also causes problems.
Things to check: horn angle, placement, pressure against embouchure. All with just the mouthpiece and then try back with the entire trumpet.