The opening produced by the air separating the lips is called the lip aperture. One opening and closing of the lips by the air is a cycle which encompases four phases. The strength and volume of a brass tone depend on the quality and amplitude of the lip vibration as well as the size of the mouth cavity. The throat cavity, mouth cavity, mouthpiece and brass instrument are the resonating chambers. Breathing To produce a good tone and sustain musical phrases a player must utilize adequate breath support.
Correct posture is the first place to focus attention for the breath.
Articulation Articulation is the tonque's manipulation of an air stream to create a particular emphasis on a tone. The beginning of a tone that is not slurred is started with the tongue usually in either a Tu or a Thu position behind the top teeth or on the roof of the mouth just behing the top teeth. The tongue starts the attack and immediately after the tongue starts the tone it moves downward to reside behind the bottom teeth. Problems that are music educators find in brass players are students who tongue through the teeth and students who stop the tone with the tongue and not the air. Overtone Series and Related Acoustical Information Brass instruments isolate the natural overtone series by the vibration of air in a tube used as a resonator.