Low brass players necessarily have a great interest in learning to efficiently and effectively move air through their instruments. Tubas and bass and contrabass trombones require that their players generate tremendous airflow in order to produce and sustain a tone, and the euphonium, baritone, and smaller trombones are not far behind. Many teachers and players—myself included—devote at least a small part of each day’s practice time to performing breathing exercises, aerobic exercises, or both, in order to increase the efficiency with which we move air. Unsurprisingly then, when you ask the average low brass student how one produces a full, resonant tone quality, most will unhesitatingly answer “by using lots of air.” Sadly, this answer is incomplete. Airflow is really only part of the equation; one might even say it is only a way of getting to the means by which one really produces a full sound.
Think for a moment about other families of instruments. On string instruments the fullest sound is produced when the bow is moved across the string in such a way that the horsehairs contact the string evenly across the entire width of the bow, and when as much of the bow’s length is used for each note as the musical context will allow. This activates the string in such a way that it vibrates more vigorously. (String players, please forgive my very rudimentary explanation!) Similarly, using the heaviest gauge string that a particular player and instrument can handle will ensure that the greatest possible amount of vibration occurs on each note.
Or perhaps woodwind instruments are more familiar to you. Beginning clarinetists will typically use a #2 or #2.5 reed. While these thinner reeds do not produce the full sound of their thicker counterparts, the weaker embouchures of young players cannot yet handle thicker reeds. Teachers typically want their students to move to #3, #3.5 or greater as soon as possible, though, because the thicker piece of wood means that there is more vibrating area, and thus a richer and fuller sound is produced.
So what is the relevance of all of this to brass players? Just as more string vibrating more vigorously produces a fuller sound on a string instrument, and as more wood vibrating more vigorously produces a fuller sound on a reed instrument, so more “lip” vibrating more vigorously produces a fuller sound on a brass instrument. While moving air efficiently and energetically is important for us as brass players, the purpose of moving that air is to activate the vibration of the lips in the mouthpiece. On brass instruments the fullest, most resonant, most pleasing sound is produced when the greatest possible amount of flesh is vibrating inside the mouthpiece for a given pitch and dynamic level. When the lips do not vibrate freely in response to the airflow provided or only a portion of the lip surface inside the mouthpiece is able to vibrate, the sound quality will be poor no matter how much air one blows into the instrument.
It behooves us therefore as low brass players to focus our energies in practice not only upon airflow, but upon enabling the most efficient and active lip vibrations possible. How do we do that? First, by ensuring that the mouthpiece selected is well-matched both to the instrument being played and the physical characteristics of the player’s embouchure. The cup diameter in particular needs to be wide enough to accommodate free movement of the player’s lips; those with fleshier lips will thus need to use a wide-diameter mouthpiece compared to those with thinner lips. Beyond equipment selection, the prescription for encouraging freely vibrating lips should be obvious: daily practice, including regular and systematic addressing of playing fundamentals. Mouthpiece buzzing, long tones throughout the range, flexibility studies, and range extension exercises (in both directions) are of particular importance. That these things be done daily cannot be overemphasized; because sound on brass instruments is produced by vibrating a part of the body that is not used for that purpose in other activities, daily exercise of that part of the body is vital so that these structures are able to form an embouchure that will vibrate readily (i.e. with minimal muscular effort exerted by the player) in response to the airflow provided.
Airflow is so vital for all wind instrumentalists, and for low brass players in particular, but it is only a means to an end. That air is only useful insofar as it activates vibration in the lips, and if a full and resonant tone is desired the lips need to be able to vibrate freely and vigorously, and with minimal muscular effort. Selecting the right mouthpiece is an important part of this, but the most important thing here is the same as it always is for musicians: “practice, practice, practice!”