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.
Diapason [noun] a family of organ tone which is not imitative of any other instrument, comprised of open cylindrical metal pipes. Diapason stops are the backbone of the organ ensemble and will appear at several pitch levels and usually in every division of the instrument. Also, a stop of diapason tone.
Diatonic Chest [noun] a windchest in which the bass pipes are placed at the extreme ends of the chest, and the treble pipes in the middle, with one side of the chest containing the notes C, D, E, F#, G#, and A#, and the other side C#, D#, F, G, A, and B. Compare with Chromatic Chest.
Direct-Electric® Action [noun] - The trademark name of the electro-mechanical action developed by John Wicks in 1914 and used by Wicks Organ Company of Highland, Illinois. This is the first electro-mechanical action developed and patented. While the patent has expired, the term "DIRECT-ELECTRIC®" is trademarked and refers only the the chest action as manufactured by Wicks Organ Company. Also used as a generic term for any electric unit action in which an electromagnet directly opens a valve under the pipe foot.
Divided Stop - a stop activated by two drawknobs, one for the treble pipes and another for the bass pipes, allowing either half to be used independantly.
Division - A number of ranks of pipes which are played from the same keyboard or couplers, and are usually located together in the same part of the organ. For example:The Swell keyboard plays the pipes of the Swell Division, and the Swell division can also be played from the Great keyboard via a coupler.
Divisional Piston [noun] - a piston on an organ console which can only be programmed to turn on or off stops within one division. Compare with "General Piston".
Dolcan [noun] - an organ flue stop usually soft in volume, bright but diminutive, nearly always at 8' (unison) pitch, and frequently paired with a similar rank tuned sharp as a celeste. Comprised of open metal pipes, cylindrical or inverted conical (wider at the top than at the mouth) in shape.
Doppelflöte [noun] - an organ flue stop whose wooden pipes each have two mouths on opposite sides of the pipe.
Doublette [noun] - on French organs, a 2' diapason stop.
Drawknob [noun] a stop control, shaped like a small, elongated doorknob, which slides outward to turn on a stop, and inward to shut it off.
Dulciana [noun] - an organ flue stop usually soft in volume, comprised of open metal cylindrical pipes. Often paired with a similar rank tuned sharp as a celeste.
Duplex Chest [noun] A chest so constructed as to allow the ranks of pipes placed on it to be played independantly from either keyboard. In effect, each rank becomes a stop on both keyboards.
Duplexing [noun] a technique in which one stop is made independently available on two different keyboards, usually at the same pitch.
Dupré, Marcel [1889-1971] French composer and organist. Succeeded Charles-Marie Widor as organist of St. Sulpice, Paris, 1937. Professor at Paris Conservatory.