To help those who want to understand pipe organs better, we have put together a brief glossary of words related to pipe organs.
1) An Organ is a musical instrument containing sets of pipes that produce sound when activated by air. The term “organ” also refers specifically to the pipes and their associated mechanism as opposed to the console, blower and other components.
2) A Pipe is a resonator made of wood or metal which, when activated by air, produces a pitch (frequency). The length of the pipe determines the pitch. The tone may be produced by the same mechanism as a whistle (flue pipe) or by a vibrating metal reed (reed pipe) as in a clarinet.
3) The pipes sit on a Chest that holds air pressure and the mechanism that allows air into an individual pipe or group of pipes.
4) The Blower is the device that provides the organ with its air. It consists of a motor and a series of fans to produce a certain volume of air at a certain pressure.
5) The Reservoir is a device that supplies a constant flow of air, at a specific pressure, to the chest. It relies on a weighted, movable top, hinged by leather and a valve to accomplish this task.
6) The Console is the control center of the organ containing the keyboards, stops and other controls.
7) A Stop is the control that turns a group of pipes on or off. “Stop” also refers to a group of pipes of the same tone color with one or more pipes for each note on the keyboard. Some stops (called “mixtures”) may contain up to four or five pipes per note.
8) A Manual is a keyboard played by the hands as opposed to the keyboard played with the feet (pedals).
9) The Pedal is the division of the organ associated with the foot pedals, its pipes and mechanisms. This division contains the lowest pitches of the organ.
10) The Great is the division of the organ associated with the lower of the two keyboards and its associated stops and mechanisms. It is usually placed in the most open, prominent position in the organ.
11) The Swell is the division of the organ controlled by the upper keyboard with its associated stops and mechanisms. It usually includes an enclosure around the pipes with one side having pivoting louvers to adjust the volume of these stops.