reed instrument

Any of a class of wind instruments that uses a single or double flexible reed made of cane, metal, or plastic. The reed vibrates under pressure within an airtight enclosure (the mouth, windcap, bellows, or airbag as in bagpipes) and acts as a valve to let pulses of pressurized air into a tubular resonator (the body of the instrument). Single-reed instruments, where the reed vibrates against the material of the instrument, include clarinets and saxophones; double-reeds, where the reeds vibrate against each other, include oboes, shawms, bagpipes, and bassoons. A free-reed instrument has a reed, usually of metal, that is fixed at one end and free to vibrate in a slot at the other, such as accordions, mouth organs, and harmoniums.

Most reed instruments use finger holes to alter the pitch, and can be overblown (see overblowing) by the player increasing the tension of the lips to give a note an octave or twelfth higher. They have a very large dynamic and tonal range, and are more efficient than whistles in converting energy to sound in the tenor and bass registers.