Wind instrument consisting of two or more single- or double-reed pipes, the reeds being vibrated by wind fed by arm pressure on a skin or cloth bag. The pipes are held in wooden sockets tied into the bag, which is inflated either by the mouth or by bellows strapped to the body. Melodies are played on the fingerholes of the melody pipe, or chanter, while the remaining pipes, or drones, sound single notes. Bagpipes existed by about AD 100. The early bag was an animal bladder or a nearly whole sheepskin or goatskin. Bagpipes have always been folk instruments, but after the 15th century some were used for court music, and others have survived as military instruments. An important related instrument is the Irish union (or uilleann) pipe.