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.



Table [noun] - that portion of a windchest on which the sliders and bearers rest, and beneath which are located the channels and bars.

Tannenberg, David [1728-1804] - Early American organ builder working in eastern and central Pennsylvania. Born in Saxony, he built organs mostly for German immigrant congregations -- Moravians, Lutherans, German Reformed, from his eventual home of Lititz, Pennsylvania. His instruments were small (mostly one-manual), extremely refined and gently voiced, thought by some to be in the same tradition as Gottfried Silbermann's work. Only nine of Tannenberg's organs survive.

Temperament [noun] - A tuning scheme for keyboard instruments which, paradoxically, modifies certain pitches to make the entire instrument sound more in tune. It is a well-known acoustical problem that it is impossible to fit all the pitches within an octave, if they are tuned pure (that is, by fifths). Many such schemes have been developed through the centuries to make most key centers work pleasingly in spite of the tuning problem. From the early Romantic period on, equal temperament was used to the near exclusion of any of the other schemes. In equal temperament, all pitches except the octaves are very slightly out of tune, but all key centers can be used. Today many of the historical schemes (Werkmeister, mean-tone, etc.) are being re-used as authentic period practice for early music.

Terraced Console - an organ console where the stops are arranged in terraced rows, like concave curved shelves, on either side of the keyboards. It was popularized by Cavaillé-Coll, but is being used in modern instruments for its convenience and compactness.

Theatre Organ [noun] a type of pipe organ designed to accompany silent films, very different in concept and tone from a classical (church) organ.


Tibia [noun] - a flute stop, usually of wood construction. There are many sub-varieties of Tibia, including stopped versions. Through the work of Hope-Jones, it became an important family of voices on the theatre organ, where it is almost always a large-scale, assertively-voiced wooden stopped flute.

Tierce [noun] - A partial-pitch stop which sounds the fourth overtone in the harmonic series (when bass C is pressed the tierce sounds middle E). Most often denoted as 1-3/5' in pitch (or 3-1/5' in the pedal) the tierce is usually of flute tone.


Toaster [noun] - a derogatory colloquialism for an electronic or digital organ.

Toe [noun] - the portion of an organ pipe which rests on the windchest; usually made of lead.

Toe Hole [noun] the hole in the bottom of the foot of a pipe, through which wind enters the pipe.

Toe Studs [noun] - switches located in the console just above the pedal keys and to either side of the Swell Pedals, which work the Combination Action like the Thumb Pistons do.

Toeboard [noun] the part of a windchest on which the feet of the pipes rest.

Tonal Finishing [verb] - the very exacting final adjustment of each pipe, the last step in the installation of a new organ.


Tongue [noun] the part of a reed pipe which vibrates and creates the sound; a strip of brass which is slightly curved in just exactly the right shape.



Tower [noun] a small group of very large pipes (typically 3 or 5) used as part of an organ's façade. See also Flat.

Tracker [noun] 1. a long, thin piece of wood used in a mechanical key action to transmit motion through tension. 2. Abbreviation for "tracker organ".

Tracker Action [noun] - a type of mechanical key action which uses trackers to transmit key movement to the valve under each pipe, causing the pipe to speak. The traditional method of organ construction used exclusively until the late 1800s. Contrast with "Suspended Action"

Tracker Organ [noun] an organ with tracker (mechanical) action.


Traps [noun] - percussion stops in a theatre organ.

Tremblant Doux - According to Dom Bedos, a type of tremulant that uses a springed flap within the chest which is moved back and forth by the wind itself. No wind escapes the chest.

Tremblant Fort - According to Dom Dedos, a type of tremulant in which a valve repeatedly allows small amounts of wind to escape the windway where it is mounted.

Tremulant [noun] a device for inducing a tremolo into the speech of pipes, usually by causing the wind pressure to fluctuate (but see Fan Tremulant).




Tuba [noun] - a large-scale chorus reed, voiced very broad rather than bright, an indispensible stop on large Romantic English organs. Frequently shows up as a very loud Tuba Mirabilis under high wind pressure in the Solo division of cathedral instruments.


Tubular-Pneumatic [adjective] - describing an organ, or some part of an organ which uses air-filled tubes for its key action, which connects the moving key with the valve under the pipe. Most such organs were built between 1880 and 1920.

Tuning Cone

Tuning Roll

Tuning Sleeve [noun] - the metal collar placed on the open end of a pipe which can be slid up or down to precisely adjust the length and tuning of that pipe. Traditionally, organbuilders used "cone tuning" rather than tuning sleeves.

Tuning Slide

Tuning Wire [noun] - a wire projecting upwards from the block of a reed pipe, which controls how much of the tongue is allowed to vibrate. This wire is used in the tuning and regulation of reed pipes.

Twelfth [noun] - A partial-pitch stop which sounds the second overtone on the harmonic series (when bass C is pressed the Twelfth sounds tenor G). Most often denoted as 2-2/3' in pitch (or 5-1/3' for the 16' series). the twelfth is usually of principal tone.

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