Denis Wick:"The brass player’s mouthpiece is the most important piece of equipment he or she possesses. It is as personal as shoes and should be fitted as carefully. Instruments need mouthpieces which bring out their best characteristics and players need mouthpieces that will help them realise their full potential. There is no easy answer to this complex requirement. No two players are alike and their requirements from the same instrument can be wildly different. Care taken in choosing the right mouthpiece for instrument, type of music and player can make the difference between steady progress, leading to ultimate success and wasted effort leading to constant frustration. Brass instruments are hardly ever made with really accurate keyboard-precise intonation. Manufacturers usually try to find the best intonation compromise by the intricate matching of the internal tapers. The natural harmonics of any tube are governed by natural laws and can never be perfectly in tune as western man hears the notes. A well designed mouthpiece should assist the compromise and make the instrument more usable. The perfect match can give perfect results. The best players can, with careful training, produce intonation which transcends the narrow confines of equal temperament."

Vincent Bach:"Choosing the perfect mouthpiece is often more difficult than choosing the perfect instrument. Your success as a musician depends on the choice of equipment that will do justice to your capabilities."

Vincent Bach on choosing a mouthpiece:"When selecting a mouthpiece, a brass instrumentalist should choose one with a solid, compact tone of large volume. A carefully selected Bach mouthpiece can help improve a player's embouchure, attack, tonguing and endurance. Professional musicians and advanced students prefer the musical results of large mouthpieces, such as the Bach 1B, 1C, 11.4C, 11.2B, 11.2C, 21.2C, 3C, which provide a maximum volume of tone with the least amount of effort. By opening up the lips so that they do not touch, the larger mouthpiece produces a clearer, purer tone. The large cup diameter also allows a greater portion of the lip to vibrate, producing a larger volume of tone, and keeps a player from forcing high tones by encouraging the correct functioning of the lip muscles. However, a student may find a medium-sized mouthpiece suitable. Do not select a certain mouthpiece because another player uses it. Because no two players have the same lip or tooth formation, what is perfect for one may be entirely unsuitable for the other. Bach produces many different models so that each player can find the best mouthpiece for their individual embouchure."

Mouthpieces - Rims, Shanks and Chambers