Mouthpiece (brass) Mouthpiece (brass) On brass instruments the mouthpiece is the part of the instrument placed on the player's lips. The mouthpiece is a simple circular opening that leads, via a semi-spherical or conical cavity, to the main body of the instrument. Mouthpieces vary to suit the tone of the instrument. Lower instruments also have larger mouthpieces, to maximize resonance (see pitch of brass instruments). Also, mouthpieces are selected to suit the embouchure of the player, to produce a certain timbre, or to optimize the instrument for certain playing styles. For example, trumpet and trombone mouthpieces are usually semi-spherical whereas French horn
Vibrato and shaping of the lips and facial muscles, essentially repeatedly "bending" the note. This is called lip-vibrato, and is probably the most commonly used technique of vibrato on a lower brass instrument. It is also known to give the best sound and timbre on a brass instrument and is encouraged in upper-level or militaristic style brass ensembles. Players may also produce vibrato by gently shaking the horn which varies the pressure of the mouthpiece against the lip. This is referred to as hand vibrato. It is more favored in higher brass, but does not possess the same sound quality as