A ligature is a device which holds a reed on to the mouthpiece of a single-reed instrument such as a saxophone or clarinet. The ligature must allow the reed to vibrate freely without stifling its vibrations.[1] Iwan Müller invented a metal ligature to replace twine.[2] String is still used by clarinetists, especially in Germany. Modern German mouthpieces have a groove cut into the outside of the mouthpiece to facilitate wrapping with a string ligature. Some modern clarinetists tie a shoestring around the mouthpiece to use as a ligature instead of a string because it is easier to tie.[3]
A ligature must be placed properly in order to best help performance on a reed instrument. The ligature must be slid down to where it is halfway down the thick part of the reed and the screws must not be overtightened.[4]
Ligatures are most commonly made out of metal and plated in nickel, silver, or gold. Some ligatures have rounded metal plates on the screws inside the band which wraps around the mouthpiece, giving the reed a place to lay evenly against without damaging the cane.[5]
Ligatures are also made out of wire, wire mesh, plastic, naugahyde, string, or leather. Dozens of styles and materials of ligatures are available today. Many modern Clarinetists utilise electrical tape as a ligature.