The video below is a demonstration of the embouchure setting. The demonstration is from a “C” below the staff to a double “C”, then up to G above double C. The change between the notes is actually very little. The air speed is increased as the air is compressed and stays steady. During the entire process, the body remains relaxed as if only the low “C” was being played. If the body tenses up, the higher note will not sound because the air stream will be corrupted due to unnecessary restriction.
The lip slurs demonstrate that although there is some movement, very little movement is required when changing notes. Steady air makes this possible. Once steady air is practiced, the body can gain perspective on how to react and become more efficient. Steady air is the necessary component for maintaining a relaxed state as well as efficiency.
The relaxed feeling which occurs while playing in the lower register would be the same as the upper register. The mind would focus on a continual uninterrupted air stream rather than considering the notes as separate. Before attempting the change in pitch, practice long tones by holding a low C below the staff. Play the low C as soft as possible with steady air. After several minutes the body and brain should be in a relaxed state. Then attempt two change notes by one octave, then two, then 3. Above all, remember to remain relaxed. Please feel free to comment on this blog.
Trumpet player, Licensed clinical psychotherapist.