When speaking of mouthpiece materials, a general rule of thumb states that the softer the material, the darker and less projecting the sound. The harder the material finds just the opposite.
Plastic:
Usually made into student mouthpieces. These mouthpiece prove durable and affordable. The tradeoff comes in that the sound can be bright and difficult to focus.
Ebonite (Hard Rubber):
Offers a warmer, better focused sound than plastic. Ebonite is the preferred material for classical players and jazz musicians not needing a great deal of edge and projection.
Crystal:
Very good projection and bright, but not much bottom sound.
Wood:
Though rarely used, wood is the warmest but least projecting of mouthpiece materials. It also proves less stable than rubber or plastic.
Metal–Plated Brass:
The majority of metal mouthpieces are made from plated brass. The mouthpieces are used almost exclusively for jazz playing. The most common plating is gold, however other metals are used for their different sonic properties.
Metal-Stainless Steel:
Likely the most projecting and brightest of the metal pieces.
Facing & Tip:
Where the mouthpiece meets the reed.The length of a facing is directly related to the opening of the tip. As a general rule, the longer the facing, the smaller the tip. The reverse is true for short facings. This relationship dictates many important factors for the clarinetist including reed strength, focus of sound and timbre, projection and the degree of "free-blowing".
The baffle is the area exactly opposite of the window and dictates the amount of “edge” or “bite” a mouthpiece displays. In general, the higher the baffle, the brighter and more projecting the sound. The lower the baffle, the more mellow and warm the sound.
Choosing the correct mouthpiece plays a major role in the overall success of the player’s development. Because mouthpieces are designed for a wide variety of styles, it is important to understand the mouthpieces design and intent.
Concert Band Mouthpieces:
For general concert band playing, choose a mouthpiece with a medium length facing curve and medium to medium close tip opening. This will allow your students to use a slightly harder reed and thereby create a more focused and controllable sound. The most popular concert band mouthpieces include the Selmer Paris C* and the Vandoren AL3 and AL4.
Jazz Band Mouthpieces:
Mouthpieces designed for jazz playing historically have a bigger tip opening, higher baffle and a larger chamber. These elements combine to give the jazz player greater flexibility and a larger tone. It is important to remember that this flexibility and volume also requires a great deal more control of the sound with the embouchure and air. When a student first begins using a dedicated “jazz” mouthpiece, it is usually a good idea to select a mouthpiece that will encourage a “jazz” sound yet remains more consistent in feel to his concert piece.
