Brass instrument the player of a brass instrument has direct control of the prime vibrator (the lips), brass instruments exploit the player's ability to select the harmonic at which the instrument's column of air vibrates. By making the instrument about twice as long as the equivalent woodwind instrument and starting with the second harmonic, players can get a good range of notes simply by varying the tension of their lips (see embouchure). Most brass instruments are fitted with a removable mouthpiece. Different shapes, sizes and styles of mouthpiece may be used to suit different embouchures, or to more easily produce certain tonal
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.