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
Mouthpiece (woodwind) reed. Single-reed mouthpieces are basically wedge shaped, with the reed placed against the surface closest to the player's lower lip (the "table"). The player's breath causes the reed to vibrate, which in turn causes the column of air inside the instrument to vibrate. The top half to three-quarters of the table is open to the inside of the mouthpiece. As with the brass instruments, the shape of the interior of the mouthpiece can greatly affect the sound of the instrument. Mouthpieces with a large, rounded chamber will produce a quite different sound from one with a small or square chamber.