The key to good tone quality on the trumpet is a good embouchure and good air flow control.
Sound is vibration, so the quality of sound depends on the quality of the vibration. A piano has strings that vibrate, and clarinets have reeds that vibrate. Trumpet players use the vibration of their lips to produce sound.
Good lip vibration requires good conditioning of the lips and a good, steady stream of air flow through the lips.
Daily practice conditions the lips to vibrate. The less time you practice your trumpet, the less conditioning your lips are getting.
Training the lips to be relaxed yet controlled enough to hold the aperture takes practice. The primary muscles needed are in the aperture of the lips. All other muscles in the lips and face can relax. Relaxed muscles mean more vibration, but controlling the aperture requires rigidity. It takes practice to keep the center of the aperture relaxed and vibrating while the muscles in the aperture area hold the position. Good vibration produces good sound. And good control of the aperture produces good sound. Playing long tones at pp helps you feel how to relax and control the lips.
A good, steady stream of air is needed to produce a good consistent sound. An unsteady stream of air will produce a wobbling and interrupted sound. To produce a steady stream of air requires controlling your breathing. Blowing air through your lips should be controlled and intentional. Moving your elbows, swaying, bumping into objects, giggling, etc, will disrupt your air flow.
Practicing long tones at pp will help you feel how well you are controlling your air flow. The goal is to feel how to produce a good, soft, steady tone. Hold your aperture and control your air stream while relaxing the center of lips inside the aperture. This is tricky to do! But with daily practice, you will learn how to control your aperture and air flow. Pay attention to the relaxation of your lips in and outside of the aperture, the muscle control in your aperture, and the muscles needed to control your air flow.
Experiment and identify what you helps you to produce a good, long, steady tone.
How long should a note be held? Hold it at least for four counts at a metronome speed of 60 each day for each pitch in your range. This is a great way to warm up too. Also, remember to let your lips rest. Playing with rested lips helps you practice good technique.
