These pages comprise a dictionary of terms relating to the pipe organ. Please keep definitions to a few sentences, and do not include pictures or sound clips. When more space is needed for a term, a new page can be created for it.


Bach, Johann Sebastian [1685-1750] - Baroque-period organist, composer, and church musician, arguably the most important composer of organ music. Most prominent member of a large family of musicians, including several of his sons, he was the last bloom of the Baroque period, synsthesizing aspects of the French and Italian styles into his native German heritage, and transcending them all. Organ music includes Toccatas, Preludes and Fugues, Fantasias, etc., and much service music based on the German Lutheran chorale tradition.

Backfall [noun] a lever used in a mechanical action to convert "push" motion into "pull" motion.

Backfall Bridge

Balanced Action

Band Organ

Barker Lever [noun] - a pneumatic device used in some large mechanical-action organs for reducing the amount of force needed to depress keys. First successfully introduced by Cavaillé-Coll in his ground-breaking instrument at St. Denis in 1841, but versions of it are still being built today.

Barpfeife [noun] - an 8' manual reed with short resonators, yielding a soft growling tone.

Beard [noun] a feature of some wooden flue pipes, a piece of wood protruding horizontally immediately below the mouth, extending for the entire width of the mouth. Used to improve pipe speech

Bearers [noun] in a slider chest, the pieces of wood between the sliders on which the toeboard rests.

Bearing Shaft

Beating Reed [noun] a reed or reed pipe in which the reed (tongue) beats against the shallot, the type of reed most commonly found in organs today. Synonym: Striking Reed. Compare with Free Reed.

Bedos, Dom (François Lamathe Bédos de Celles de Salelles) [1709-1779] - Dom Bedos de Celles OSB was a monk of Holy Cross Abbey in Bordeaux in France. He built organs and wrote textbooks on organ building.

Bell [noun] a flared top surmounting some flue pipes and reed pipe resonators.


Bench [noun] that portion of an organ console on which the organist sits whilst playing.

Block [noun] 1. the portion of a wooden flue pipe at the base, to which the sides and cap are fastened, and in which the windway is usually cut. 2. the portion of a reed pipe into which the shallot, tongue, wedge, and resonator are fitted, and over which the boot fits; commonly made of lead.

Blockflöte [noun] - a flue organ stop, usually open metal and at 4' or 2' pitch, yielding a bright flute tone. Its name is the German word for "recorder".

Blockwerk [noun] Before the invention of the device to turn on and off individual ranks of pipes, now called "stops", an entire division in which all the ranks always speak at once, like a giant mixture. Obsolescent in the 14th century.

Blower [noun] a device for creating the wind (compressed air) on which an organ speaks.

Body [noun] the portion of a flue pipe above the block or languid.

Bombarde [noun] 1. a chorus reed of powerful tone. 2. a division that includes powerful chorus reeds.

Bombardenwerk [noun] - German term for the Bombarde division, see above.

Book Pneumatic

Boot [noun] - a hollow removable shell that covers the tongue and shallot of a reed pipe, fits over the block, and includes the toe which rests on the windchest.

Bore [noun] - synonym for Toe Hole.

Borrowed [adjective] - a term used to describe a stop with no pipes of its own, which uses pipes from another stop. The two stops are typically at the same pitch but played from different keyboards, otherwise the term "Unification" is usually used.

Borstwerk [noun] Dutch synonym for Brustwerk.

Bottom-board [noun] a board which forms the bottom (or a portion thereof) of a wind chest, often removable for maintenance.

Bourdon [noun] - a stopped flute, of wood or metal, found at 16', 8', or 4' pitches, in all divisions of the instrument. From the French word for "buzz", German synonym is "Gedeckt", British synonym is "Stopped Diapason".


Bovenwerk [noun] - Dutch synonym for Oberwerk.


Brustpositiv [noun] - another name for "Brustwerk", see below.

Brustwerk [noun] a division named because of its placement in the "breast" (brust) of an organ; that is, approximately in the center of the case, above the keydesk. Because of the height limitation it is traditionally the highest-pitched division in the Werkprinzip scheme, with room for pipes of a maximum 4' length. Frequently constructed with doors on the front.

Brødrene Torkildsen — Norwegian organ building firm.



Buxtehude, Dietrich (1636-1707) - an important pre-Bach composer, organist and church musician. He worked in north Germany or Denmark, and Bach visited him as a young man, to hear the Abendmusiken concerts for which he was famous.

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