The most important part of a clarinet is arguably the mouthpiece. The mouthpiece of the clarinet is where the reed sits and vibrates and is the part of the instrument around which the player puts his lips. Choosing the best clarinet mouthpiece means determining what the player can do physically and musically, selecting a satisfactory material, picking dimensions suited to the needs and tone desired of the player and physically trying the mouthpieces in consideration with new reeds in different settings.
The first step in choosing the best clarinet mouthpiece is to assess player ability. A player who is just starting out still needs good response and control, but they don't always know how to care for mouthpieces properly and are still developing the techniques necessary to complete basic tasks on the instrument. Inexpensive mouthpieces of plastic are usually fine for these players. More advanced players, however, are more aware of the subtleties between mouthpieces, play in a wider variety of environments that demand different tones and projection rates and have more developed embouchures. These players often need mouthpieces of different quality, physical dimensions and materials to get the sound and response they want.
Once a player knows the level of ability, he has to decide which material should make up the clarinet mouthpiece: plastic, hard rubber, metal and glass or crystal. Most beginners play on plastic mouthpieces because they are both durable and inexpensive. Hard rubber is probably the material players prefer most. It is slightly more expensive than plastic, but it blends better in ensembles and has a consistent, darker tone with strong fundamentals and lots of overtones. Metal mouthpieces project more and thus are better suited to solo playing, particularly jazz, whereas crystal mouthpieces are extremely stable but fragile.
Following material selection, assess the dimensions of the each clarinet mouthpiece. Three measurements impact the playability and sound of a clarinet mouthpiece, including the tip opening, facing or lay, and baffle. The tip opening refers to the space between the tip of the reed and the mouthpiece. The facing or lay refers to the length of the curve from the tip of the reed to where the reed touches the mouthpiece. The baffle is the surface of the mouthpiece opposite the window, or opening over which the reed sits.
Look at the clarinet mouthpiece dimensions under the lenses of air resistance, embouchure and response. Regardless of which mouthpiece a player picks, the mouthpiece should be able to blow freely with the right hardness of reed so the player does not have to work too hard. The player's embouchure determines how much pressure the player has to put on the mouthpiece to get a focused sound. Response is a combination of these two elements, with a good mouthpiece producing air resistance conducive to the production of both a smooth legato and short staccato.
Typically, a narrower tip opening creates more resistance. It thus tends to be easier to play and has a darker sound. Wider tip openings are more free-blowing, requiring more control. A clarinet mouthpiece with this type of tip opening is both louder and brighter.
When considering facing, a longer facing provides a commanding sound with easy low notes because the reed vibrates more. Clarinet mouthpieces with long facings require better muscular control. A short facing lets a player reach high notes easily, but only a small part of the reed vibrates, necessitating better breath control. A mouthpiece with a medium face works for most players, accommodating many playing styles and reed types.
A good mouthpiece is a combination of the right materials and dimensions, so try many different mouthpieces to find the one that works with the player's clarinet best. Test the mouthpieces in different settings if possible. Always try the new mouthpieces using new reeds, as the idea is to pick a mouthpiece that functions even on reeds that have not been broken in as much.
One thing to avoid when selecting clarinet mouthpieces is buying them online. This doesn't mean online vendors do not have good products. It simply means that each mouthpiece cannot be exactly duplicated and stands on its own. A player has to physically try the mouthpiece to determine if it will work.