A single-reed instrument is a type of woodwind instrument that produces sound when air is blown through a single reed. The two most common single-reed instruments are the CLARINET, which has 8 letters, and the saxophone, which has 3 letters. Both instruments have a cylindrical bore and use a single reed to produce sound. The CLARINET is typically made of wood or plastic and has a range of four octaves. The saxophone is usually made of brass and has a range of three octaves. Both instruments are used in a variety of musical genres, from classical to jazz.