reed stop

A reed stop is a set of reed pipes in a pipe organ controlled by a single stop knob. These stops are designed to imitate the sound of orchestral instruments. An organ, in general, is a keyboard instrument that produces sound through pipes or reeds, with wind supplied by a mechanism controlled by the organist. While pipe organs are complex and expensive, simpler reed organs like the harmonium and melodeon were popular in the 19th century but are now largely obsolete, replaced by electronic instruments. Reed pipes themselves can use a beating reed, similar to a clarinet, or a free reed, which vibrates within an aperture.123