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organ, a musical wind instrument in which sound is produced by one or more sets of pipes controlled by a keyboard, each pipe producing only one pitch by means of a mechanically produced or electrically controlled wind supply.

Early Organs

Ktesibios of Alexandria, in the 3d cent. B.C., invented the hydraulis, in which water pressure was used to stabilize the wind supply. The pipes were arranged in rows upon the wind chest and the air was permitted to enter any pipe at will by means of wooden sliders. The hydraulis was the prevailing organ for several centuries and reappeared at intervals throughout the Middle Ages.

Evidence of the first purely pneumatic organ is found on an obelisk erected at Byzantium before A.D. 393. Byzantium became the center of organ building in the Middle Ages, and in 757 Constantine V presented a Byzantine organ to Pepin the Short. This is the earliest positive evidence of the appearance of the organ in Western Europe. By the 10th cent., however, organ building had made considerable progress in Germany and England. The organ built c.950 in Winchester Cathedral is said to have had 400 pipes and 26 bellows and required two players and 70 men to operate the bellows.

The keyboard, or manual, was a creation of the 13th cent., making possible the performance of more complex music. The earliest extant music written specifically for organ, dating from the early 14th cent., gives evidence that by then the manuals of the organ had full chromatic scales, at least in the middle registers. Organs in the Middle Ages already had several ranks of pipes, each key causing a number of pipes to sound simultaneously. All were diapasons, or principals, the pipes of timbre characteristic only of the organ, and the various pipes controlled by one key were tuned to the fundamental and several harmonics of a given tone.

The Development of the Modern Organ

The 15th cent. saw considerable development of the organ, particularly in Germany and Flanders. It became possible to sound single pipes from a rank through the use of stops. Mutation and mixture stops that produce several harmonics of the unison pitch came to be used in combination with the unison to vary tone color. Solo stops imitative of other instruments, mainly flute and reed pipes, were added, and the pedal became standard. Until the 19th cent., Italy and England preferred an organ with no pedals.

It was the Flemish and German builders who developed the organ of distinctive and contrasting timbres, and the peak in organ building was reached in the German organ of the baroque, as described by Michael Praetorius in his Syntagma musicum (1618). The greatest organ builder, perhaps of all time, was Gottfried Silbermann (1683–1753) of Dresden. His organs produced a light, transparent tone, ideal for the performance of the great baroque polyphonic music. After this period the art of organ building degenerated, and the organ lost its place in the center of musical life.

The 19th-century desire for a highly expressive organ led to the obscuring of diapason tone by the large number of stops imitative of orchestral tone and to the common employment of the swell and the crescendo pedal. The swell involves enclosing one or more divisions of the organ in a wooden box on one side of which are shutters opened or closed by means of a swell pedal; the crescendo pedal, when gradually opened or closed, adds or takes off stops one by one.

The early 20th cent. saw the electrification of the mechanical parts of the organ, fulfilling the trend toward monstrous size and overwhelming power. In America, this large “king of instruments” became a feature of municipal auditoriums, movie palaces, churches, department stores, schools, and many other institutions. The master architect of these colossal orchestral organs was Ernest M. Skinner. In the early 20th cent., however, Albert Schweitzer was active in the preservation and restoration of many fine old organs, and there was a movement back to the ideals of Silbermann. In the United States, Walter Holtkamp, beginning in 1932, and G. Donald Harrison, in 1935, became the leading figures in this movement. Harrison designed many organs suitable for the performance of music of all periods. In the United States much of the repertoire was performed by the two leading organists of the era, E. Power Biggs and Virgil Fox. By the beginning of the 21st cent., European and American organ builders continued to concentrate on early principles for the construction of their instruments.

Music for the Organ

The organ repertory is vast and varied. The great organ masterpieces of the 17th and 18th cent. include works by John Bull, Handel, Jan Sweelinck, Girolamo Frescobaldi, and Dietrich Buxtehude. In the compositions of J. S. Bach the capabilities of the organ found their most magnificent expression.


See H. Gleason, Methods of Organ Playing (5th ed. 1962); C. F. Williams, The Story of the Organ (1903, repr. 1972); W. L. Sumner, The Organ (rev ed. 1973); P. Williams and B. Owens, The Organ (1988); C. R. Whitney, All the Stops: The Glorious Pipe Organ and Its American Masters (2003).

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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(in biology), a part of the body of an animal or plant that performs one or several characteristic functions. Examples of animal organs are the brain, heart, eye, liver, and stomach, while the root, stem, leaf, and flower are examples of plant organs.

An organism is able to act as a unified whole owing to the interconnection and interaction of its organs (seeCORRELATION). Organs are classified according to their principal functions; for instance, animal organs can be locomotor, digestive, respiratory, circulatory, or excretory, and plants have photosynthetic and absorptive organs. Reproductive organs are common to both animals and plants. Functionally complementary organs are united into systems that ensure the principal life functions of the organism. Each organ usually consists of a number of tissues, each of which performs a narrower function than the organ as a whole. Most organs perform several functions. In comparative studies, a distinction is made between analogous and homologous organs (seeANALOGY, HOMOLOGY).

In the development of a species, reduction or increase in the size, complexity, and function of an organ is a consequence of natural selection and of new requirements of the organism in response to environmental changes. Examples of such structural and functional modifications in organs are the reduction of eyes in burrowing and speluncar animals, the reduction of stamens in labiates and scrophulariaceous plants, the development of lungs in a number of terrestrial vertebrates, and the well-developed root system of plants that grow in arid habitats.



a multibarrel weapon used in various armies in the 16th and early 17th centuries. The name “organ” originated from its external resemblance to the musical instrument.

The organ had from six to 24 or more barrels (muskets, mortars, and small-caliber cannon) secured in several rows on a special shaft or on frames. The detonators of the barrels in each row were connected by a single groove, making it possible to fire a simultaneous volley. Organs were usually placed on wheeled carriages. Similar guns in Russia were called soroki. They went out of use with the invention of case shot.



a wind keyboard musical instrument consisting of a set of wooden and metal pipes of various sizes and a pneumatic system (an air-compressing mechanism and conductors) contained in one cabinet, and a separate control panel, or console. In addition to keyboards for the hands (manuals) and feet (pedal board), the console houses the handles of various levers that connect (couple) the keyboards and switch on the ranks, as well as devices that control the volume of sound.

An organ may have from one to seven manuals, each including up to 72 keys, and a single pedal board (usually, up to 32 keys). Some modern organs have a second pedal board. Organs may have up to several thousand pipes (sounding mechanisms), which are divided into groups called ranks, or registers. The total number of ranks in an organ depends on the size of the instrument. A small organ may have up to ten, and a large one may have several hundred. Each rank has a characteristic timbre and is controlled by a lever or button. Music for the organ is written on three staffs. Usually, the ranks are not indicated.

There are three main operating systems, or actions. In an organ with mechanical (tracker) action, the energy of the movement of the organist’s finger is transmitted from the key to the valve, which is opened by means of many trackers (rods), sliders, wooden brackets and blocks, permitting air to enter the pipe. With pneumatic action, wind pressure transmits an impulse of air through pipe-conductors to a pipe valve, opening it. Pneumatic action organs are not common. Electric action transmits the organist’s “instructions” from the keys to the pipes by means of electric cables. The best type of modern organ offers a combination of mechanical and electric action.

The volynka, the ancient Chinese sheng, and the European panpipes are predecessors of the organ. A water organ known as the hydraulus was invented in the third century B.C. in Greece.

Among the composers who have contributed to the organ repertoire are J. S. Bach, Mozart, Beethoven, Haydn, Brahms, C. Saint-Saëns, B. Britten, A. K. Glazunov, A. F. Gedike, D. D. Shostakovich, A. Kapp, and A. Kalniņŝ. The popularity of the organ in Europe increased most rapidly in the 16th through 18th centuries.


Glebov, I. “O polifonicheskom iskusstve, ob organnoi kul’ture i o muzykal’noi sovremennosti.” In the collection Polifoniia i organ v sovremennosti. Leningrad, 1926.
Braudo, I. “Vozrozhdenie organa.” In the collection Sovremennyi instrumentalizm. Leningrad, 1927. (Novaia muzyka, collection 3.)
Farmer, H. G. The Organ of the Ancients. London, 1931.
Klotz, H. Das Buch von der Orgel, 6th ed. Kassel, 1960.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


A differentiated structure of an organism composed of various cells or tissues and adapted for a specific function.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


a. a large complex musical keyboard instrument in which sound is produced by means of a number of pipes arranged in sets or stops, supplied with air from a bellows. The largest instruments possess three or more manuals and one pedal keyboard and have the greatest range of any instrument
b. (as modifier): organ pipe
2. any instrument, such as a harmonium, in which sound is produced in this way
4. Biology a fully differentiated structural and functional unit, such as a kidney or a root, in an animal or plant
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005