Selecting a new brass mouthpiece can be an intimidating experience. However, with a bit of knowledge and understanding, finding the right mouthpiece can make playing even more enjoyable for both the performer and the listener.

When changing a mouthpiece, it is imperative that the switch is done for the appropriate reasons. Changing mouthpieces to accommodate shortcomings in core fundamentals in a player can be detrimental to the growth of the musician and will only lead to further problems down the road. Reasons that should be considered in determining when it is time to switch mouthpieces include, but are not limited to: better tone, endurance, intonation, range, flexibility and articulation. It is important to realize that each player is unique in the approach they have to playing the instrument. When considering the variables in the size of oral cavity, dental structure, thickness of lips and lung capacity, it can be concluded that there will be no one particular mouthpiece that can be recommended to every musician.

The correct mouthpiece takes into account both the musician’s physical attributes and the anatomy of the mouthpiece. In order to choose the proper mouthpiece, it is important to understand how the different components of the mouthpiece function. The correct mouthpiece will be one that is most comfortable and offers the fewest compromises in order to achieve the desired results.

There are four main variables to the brass mouthpiece; understanding how each affects the end result will enable the musician to make informed decisions on how to begin selecting the best mouthpiece. They include: the rim, cup, throat and backbore.

The rim of the mouthpiece is the point of contact between the musician and the instrument. This is critical because it is what the player feels and is what creates the seal. Generally, a rounder rim will allow greater flexibility, yet sometimes tires the player sooner. A flat rim often feels the most comfortable, but tends to hold the lips in a fixed position, thereby reducing flexibility.  For most players, a compromise in rim contour is preferred. There should be some curvature to allow for flexibility but with enough surface to improve endurance.

There are two important measurements to the cup: the diameter and the volume. The cup diameter, or inner rim diameter, determines the amount of lip that will vibrate inside the mouthpiece. A smaller cup diameter may improve upon the upper register and endurance, but both tone and volume will be sacrificed. A larger cup diameter will enable more of the lip to vibrate, resulting in a fuller sound as well as strengthening lip control and endurance.

Cup depth plays an important role in shaping the tone quality, color and intonation. A shallow cup will facilitate an easier higher register playing, but offer a thinner sound. A deeper cup will produce a richer, more resonant sound, but the upper register will require a greater effort. The player’s needs and characteristics determine where the compromise will be regarding the cup size.

The throat is the smallest point of the mouthpiece. It is the area that connects the cup to the backbore. Its function is to control the resistance. If the throat is too small, the sound will be thin and uncolored; if it is too large, then there will not be enough resistance and cause the player to work harder, decreasing endurance.

The backbore is the transition from the mouthpiece to the instrument. It is the taper that connects the throat of the mouthpiece to the mouth pipe of the instrument. The size and length of the throat and the diameter of the mouth pipe determine the amount of taper. A tighter tapered backbore offers more brilliance and control while providing more resistance. This generally will assist a player in the upper register. If the backbore is too small, the resulting sound is stuffy and lacking resonance. A large backbore offers a darker, thicker sound with more depth and volume with less resistance. But, if there is not enough resistance, the resulting sound will become harder to control and intonation less stable.

How to Choose
When it comes time to choose a new mouthpiece there are several key aspects that should be tested. It is important to determine how the player and mouthpiece interact in regards to tone, range, volume, intonation, articulation, endurance and flexibility. Each of these categories should be tested thoroughly, and one should always keep in mind what the end goal is.

With a clear goal on where improvement is desired and an understanding of how the various parts of the mouthpiece function, it will become easier to begin selecting mouthpieces to test. Careful, thoughtful playing of scales, exercises, études and other basic fundamentals that focus on the particular aspect where improvement is desired will enable the performer or teacher to judge how a particular mouthpiece responds. If, for example, the player is looking for less effort in the high range, it is likely that a shallow cup will help achieve these results. But, by choosing a shallower cup, the overall tone may become less full, resulting in a different problem. If the player is looking for greater flexibility, choosing a thinner and more rounded rim will help, but the result can be a mouthpiece the tires the player more easily.

In the end, it is important to remember that there is no perfect mouthpiece; the best will be the one that achieves the goal with the most comfort and least compromise.