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.


Cadereta [noun] - in Spanish organs, the Ruckpositiv or chair organ, placed behind the player's back.

Calcant -- In hand-blown organs, the signal device from the performer's area to the person operating the bellows to begin working the bellows or to stop. Frequently in the form of a stop knob.

Cap [noun] a hollow cylinder, closed at one end and usually lined with felt, placed tightly over the top opening of some flue pipes. It is one of two common ways of stopping a pipe, the other being a plug-like stopper.

Capture System [noun] a type of combination action which can "capture" the current registration and store it for later recall via a piston or toe stud.

Casavant Frères [noun] An important Canadian organ-building firm which was founded in 1879, although the father Joseph Casavant was working as early as 1840. Their early style reflected the French symphonic ideal, but the English Cathedral sound soon influenced their instruments. After World War II they became an exponent of the organ reform movement, building many successful instruments with tracker action in the Werkprinzip style. Since the 1980's they have been building in many styles. Their instruments reflect the highest quality both tonally and mechanically.



Cavaillé-Coll, Aristide (1811-1899) - Undeniably the most important French organ-builder of the 19th century. He revolutionized organ design and organ tone, and through his ingenuity laid the basis for many developments of the modern organ. He increased wind pressures for power and employed the Barker lever as a means of overcoming the resulting key resistance. He built reed stops with harmonic (overblown) trebles to strengthen and balance their upper registers. He developed the divided windchest, with the stops divided into fonds (foundations) and jeu de combinaison (upperwork and reeds) to increase tonal flexibility. His instruments always displayed the highest quality, and he built or contributed to many of the famous organs in France and elsewhere. Overshadowed by the clearer, North-European-inspired instruments of the Organ Reform Movement of the 20th century, his style has returned to strong influence since about 1985.

Celeste [noun] - an organ stop which is tuned slightly off-pitch so as to produce a tremulant or vibrato effect; some such stops include both a normally-tuned rank and one or more off-pitch ranks.

Chair Organ [noun] in early English organs, a secondary division placed behind the organist's back and sometimes incorporating the organist's bench (chair). Equivalent in placement to the German Ruckpositiv. The name Chair eventually evolved to Choir.

Chamade - the expression "En Chamade" in the name of a stop indicates that the pipes of that stop are mounted horizontally protruding from the front of the organ case. It was common practice to mount a trumpet stop thus in Iberian Organ building.

Chamber [noun] - a separate room in which the chests and pipes of an enclosed division stand, the sound reaching the hearers through an opening equipped with a set of Swell Shades. In older or small organs a Swell Box was used to contain the pipes which were under expression.

Channel [noun] 1. an open space within a windchest which conveys wind to all pipes of a single note. 2. a wind conveyance in a windchest to transmit wind to an offset chest.

Chest [noun] - short for "Wind Chest".

Chiff [noun] - the short distinctive noise made by some organ pipes as they start to speak, before their steady tone is established. Chiff can be controlled or eliminated by nicking, q.v.

Chimes [noun] - a set of tuned bars or tubes which are struck by hammers operated by air or electric motors controlled by the keyboards and stop controls. The effect is that of a stop of bells.

Chimney [noun] a tube surmounting the tops of certain types of stopped flue pipes, markedly smaller in diameter than the body of the pipe.

Chimney Flute [noun] a flue stop the pipe of which are surmounted by a tube, markedly smaller in diameter than the body of the pipe.

Choir [noun] In the English and American traditions, a softer division of an organ intended for accompanying. It is found only on organs of three or more manuals, and is usually played from the lowest keyboard on the console. See also Chair Organ.

Choralbass [noun] - a 4' diapason stop in the pedal division. One of its uses is to play a tenor melody in choral-based music.

Chorus Reed [noun] - a reed stop which is made to blend with other reeds and with the Diapason chorus to build up a grand bright sound. The stop-names usually are those of orchestral brass instruments: Trumpet, Tuba, Trombone.

Chromatic Chest [noun] a windchest on which the pipes are placed chromatically, lowest to highest, like a piano keyboard. Compare with Diatonic Chest.

Cinema Organ [noun] - see Theatre Organ.

Cipher [noun] a pipe or note which will not turn off when it should.

Clarabella [noun] - an open flute of wide scale, usually at 8' pitch.

Clarinet - An imitative reed stop. Usually constructed with half-length resonators, it is a successful imitation of its orchestral model. In the German Romantic tradition it was often made as a free reed.

Clarion - A chorus reed at the octave above unison. This is usually at 4' pitch, but could be 8' in the pedal. The French spelling is "Clairon".

Clicquot, François-Henri (1732-1790) A French organ builder of the eighteenth century, one of the most important builders in the French Classic style. Son and grandson of organ builders, he was centered in Paris, and built important instruments at Notre Dame and Saint Sulpice.


Closed Shallot

Combination Action [noun] a system for storing registrations and recalling them at the touch of a piston or toe stud.

Common Metal (see Hoyt Metal)

Compass [noun] a specification of the lowest and highest notes on a keyboard. Modern manual compass is 61 notes, C to C; modern pedal compass is 32 notes, C to G. Many other compasses have been used historically.

Composition Pedal

Compound Stop [noun] - an organ stop in which two or more pipes are used for each note. This includes Celestes and Mixtures.

Compton, John & Co Ltd [proper noun] - a company of English organ builders who specialised in totally enclosed extension organs. A large example of their work is installed at Downside Abbey in Somerset.

Concave [adjective] an attribute of some pedalboards (including the AGO standard pedalboard) whereby the pedals are arranged along a shallow vertical arc, such that the pedals at the center are lower than those at the extreme treble and bass ends of the pedalboard. Concave pedalboards are usually also radiating.

Concussion Bellows [noun] - a small square or wedge-shaped bellows that is inflated against spring pressure, and intended to absorb spikes or irregularities in the wind pressure. It does not contain a valve to cut off the wind like a "wind regulator".


Cone Chest [noun] a type of ventil chest utilizing cone-shaped valves, found in some 19th-century German organs.

Cone Tuning - the traditional method of adjusting the precise tuning of an open pipe. It involves bending the top of the pipe inward (to flatten) or flaring it outward (to sharpen) using a brass cone-shaped wedge.

Console [noun] the portion of an organ, similar to the keydesk excepting that it is usually detached from the organ and has its own case-work, containing the keyboards, stop controls, and other controls used by the organist during performance. Consoles are usually used with organs featuring direct-electric, electro-pnuematic actions, and sometimes also with mechanical actions.


Cornet [noun, pronounced cor-nay] a compound stop of a standard composition usually used as a solo stop. Almost always sounding 8', 4', 2-2/3', 2', and 1-3/5' pitches, the voicing of the individual ranks can vary greatly from era to era and by national school. The pitches sounding together create a reedy and very commanding sound. Can appear as a single five-rank stop, as a single stop with fewer ranks, or with the pitches available separately. Important stop in early music and indispensible for French Baroque music.

Cornopean [noun] - a chorus reed stop, usually in the Swell division, its tone thicker and darker than the French Trompettes, with a horn-like quality. Invented and perfected by British builders.

Couperin, François

Coupler [noun] a device that connects pairs of keys so that when one key is depressed, the other is played. This connection may be mechanical or electric.

Cremona [noun] - British usage for the Clarinet or Krummhorn stop.

Crescendo Pedal [noun] a rocking pedal, placed just above the pedalboard next to the swell pedal(s), which gradually adds or removes stops as it is tilted forward or backward.

Cut-Up [noun] the distance between the lower and upper lips of a flue pipe, usually expressed as a fraction of the width of the pipe's mouth. All other things being equal, lower cut-ups produce more harmonics.

Cymbal - A high-pitched mixture stop, French spelling "Cymbale". In the theatre style, a percussion stop imitating the orchestral model.

Cymbelstern [noun] - see zimbelstern

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