Single-reed instrument mouthpieces are basically wedge-shaped, with the reed being placed against the surface closest to the player's bottom 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 large, a rounded chamber will produce a quite different sound from one with a small or square chamber.
The distance between the tip of the mouthpiece and the tip of the reed is known as the tip opening. The tip opening has little effect on tone, which is more affected by the design of the mouthpiece's chamber (interior space).
The facing (or lay) is a curved section that leaves the flat table and continues to the tip of the mouthpiece. The length of a facing — defined as the distance from the tip of the mouthpiece to the point where the reed and mouthpiece meet — can vary. Different facing lengths have different response properties.
The single reed is held tightly against the mouthpiece by a ligature. Anything that can hold the reed on the mouthpiece may serve as a ligature. Commercial ligatures are commonly made of metal or plastic. Some players (including many German clarinetists) prefer string or a shoelace, which is wrapped around the reed and the mouthpiece, to commercially manufactured ligatures.
Today, as with the saxophone mouthpiece, the reed is placed against the surface (the table) closest to the player's bottom lip. However, this was not always so: The earliest clarinetists would often place the reed on top of the mouthpiece.
Bernhard Henrik Crusell was one of the first clarinetists of note to consistently place the reed against the bottom lip.
Of particular note is Reginald Kell who was known for using a "double embouchure". This is a technique popular in the UK up to the 1960s, whereby the reed is placed against the lower lip, which covers the lower teeth —as in the single embouchure— and additionally, the upper lip is tucked in between top of the mouthpiece and the upper teeth. This technique has been revived lately both in the UK and the US.
Interestingly, some clarinetists in Madagascar today still play with the reed on top as can be heard on the CD "Bémiray: Polyphonies des Hauts-plateaux" recorded on the music label Silex.
Clarinet mouthpieces are available in hundreds of styles from dozens of manufacturers around the world. Mouthpieces are often named after famous performers who contribute to their designs. Popular mouthpiece makers include Selmer, Vandoren, and the Woodwind Company (presently owned by Leblanc).
Differently sized clarinets (sopranino, soprano, alto, bass, and contrabass), each require a different size of mouthpiece. One exception is B♭ and A soprano clarinets, and in some cases C soprano clarinets; as they are so close in size that players typically use the same mouthpiece on both.
Saxophone mouthpieces are available in hundreds of styles from dozens of manufacturers around the world. Mouthpieces are often named after famous performers who contribute to their designs. Popular mouthpiece makers include Meyer, Selmer, Vandoren, Otto Link, Berg Larsen, Dukoff, Dave Guardala and Yamaha.
When Adolphe Sax invented the saxophone, he specified the shape of the interior of the instrument's mouthpiece as being large and round. All saxophone mouthpieces were made in this style until the 1930s, when the advent of big-band jazz made saxophonists experiment with different shapes of mouthpieces to get a louder and edgier sound.
Between 1940 and 1960, it became common for classical saxophonists to use narrow-chamber mouthpieces, based on those designed for jazz use. These mouthpieces give the instrument a brighter and edgier sound (more high partials) than the traditional shape as designed by Sax.
One saxophone player and teacher, Sigurd Raschèr, spoke out against this change in mouthpiece design. He believed that when used in classical music, the saxophone should sound as its inventor, Adolphe Sax, had intended, and that the gradual change to narrower and "brighter" sounding mouthpieces was a distortion of Sax's tonal concept. Whenever he taught or lectured to saxophone players, Raschèr emphasized that the modern mouthpieces were not what Sax had intended, and the sound they produce, while useful to a jazz player who requires a loud piercing sound, was not appropriate for use in classical music. His students and other disciples felt that the desirable tone for a classical saxophone was a softer, rounder sound - a sound that can only be produced by a mouthpiece with a large, rounded interior (often referred to as an "excavated chamber"). His steadfast and irascible insistence in this area, while nearly all the world's classical saxophonists were moving to narrower mouthpieces (along with saxophones with a non-parabolically expanding bore) and a brighter tone, resulted in quarrels with, and alienation from, the majority of the classical saxophone world.
By 1970, narrow-chambered mouthpieces had become nearly universally popular, and mouthpiece manufacturers ceased production of large-chambered mouthpieces. This lack of supply meant that adherents to Raschèr's opinion had difficulty finding mouthpieces that would produce the tone they desired. For a period of time the only large-chambered mouthpieces were ones that had been manufactured in the 1920s and 1930s, leading Raschèr followers to search pawn shops and other sources of old instruments.
Raschèr responded to this lack of supply by engaging a manufacturer to make a "Sigurd Raschèr brand" mouthpiece, which was simply a virtual duplication of the mouthpieces that had been readily available from American saxophone manufacturers Buescher and Conn in the 1920s. The Raschèr mouthpiece is still manufactured today, among hundreds of other more modern designs.