From Wikipedia, the free encyclopedia
The pipe organ is a musical instrument that produces sound by admitting pressurized air through a series of pipes. Pipe organs range in size from portable instruments with only a few dozen pipes to very large organs with tens of thousands of pipes, causing Wolfgang Amadeus Mozart to name it the "king of instruments."  The pipe organ is also the origin of the phrase "to pull out all the stops"—meaning to make every effort or "to give it all you've got".
The organ has been described as one of the oldest musical instruments, as its origins can be traced back to ancient Greece in the 3rd century BC. The basic elements of a pipe organ are pipes (the sound-producing objects), placed on a chamber (called a windchest) that stores air under mechanically-produced pressure (referred to as wind), where access of the air to the pipes is controlled by a keyboard. Because of its constant wind supply, the organ is capable of sustaining sound for as long as the key is depressed, in contrast to other keyboard instruments, such as the piano and harpsichord, whose sound decays as the key is depressed. The organ also boasts a substantial repertoire, with music available spanning a period of over 400 years.
Modern organs usually include more than one keyboard playable by the hands (called a manual) and a large keyboard playable by the feet called a pedalboard. The most commonly-seen configuration is two manuals with a pedalboard. Large organs can feature up to five manuals, although some of the largest have even more than this.
Pipe organs are commonly found in Christian churches, as well as in some Reform and Conservative synagogues, where they are used to accompany the musical portions of the service, such as choral anthems and congregational hymns as well as parts of the liturgy. Solo organ music is generally played before and after the service. These pieces are generally called voluntaries. Pipe organs are also found in town halls and in arts centres intended for the performance of classical music, especially for transcriptions of orchestral music. In the era of silent films, large theatre organs were installed in many cinemas. Large pipe organs with automatic mechanical player mechanisms were often found in the mansions of the very wealthy in the early 20th century in America. Today, small pipe organs are often found in the homes of organists and organ lovers.
History and development
The organ is one of the oldest instruments still used in European classical music. Its earliest predecessors date to the 3rd century BC.
The word organ originates from the Latin word "organum", the instrument used in ancient Roman circus games and similar to a modern portative.
The inventor most often credited is Greek engineer Ctesibius of Alexandria, who created an instrument called the hydraulis, an hydraulic (water-powered) instrument, in the 3rd Century BC. The hydraulis was common in the Roman Empire, where its immensely loud tone was heard during games and circuses in amphitheatres, as well as in processions. Characteristics of this instrument have been inferred from mosaics, paintings, literary references and partial remains, but knowledge of details of its construction remain sparse, and almost nothing is known of the actual music it played.  The pumps and water regulators of the hydraulis were replaced by bellows in the 2nd Century AD.
Organs were also known to exist in the Byzantine Empire as well as in Islamic Spain. In medieval times, the portable instruments (the portatif or portative organ and the positive organ) were invented. Towards the middle of the 13th century, the portatives represented in the miniatures of illuminated manuscripts first show signs of a real keyboard with balanced keys, as in the 13th century Spanish manuscript known as the Cantigas de Santa Maria. Because of their portability, portatives were used for the accompaniment of both sacred and secular music in a variety of settings.
As the instruments became larger, they were installed permanently in a fashion similar to the church organs of today. At this time, organs did not have sophisticated stop controls: the organist would usually have the choice of playing on a single 8' Principal stop (see Construction) or what was called the Blockwerk. The Blockwerk consisted of the entire tonal resources of the organ, which in some cases meant a very large number of ranks ranging from 16' pitch all the way through 1' pitch and higher.
Eventually, separate controls were built to allow the organist to control whether or not each rank in the Blockwerk would sound, effectively dividing the Blockwerk into separate stops. Some of the higher-pitched ranks were still grouped together under a single stop control; these stops were the forerunner of mixtures that would be found in later organs.
Renaissance and Baroque eras
During the Renaissance and Baroque eras the organ became an instrument capable of creating numerous tonal colors, both unique and imitative. In northern Europe, the organ developed into a large instrument with several divisions, including an independent pedal. These divisions were readily discernible by the case design. This style was labeled the Werkprinzip by 20th-century organ scholars. In France, the French classical organ came into fashion, a style of building articulated most completely by Dom Bedos de Celles in his magnum treatise, L'art de facteur d'orgues (The Art of Organ Building).
In the Romantic era the organ transitioned from a polyphonic to a symphonic instrument, capable of creating a massive layered crescendo from the softest stops alone to full organ (the state in which all the stops are engaged). Through the developments of the French organ builder Aristide Cavaillé-Coll, the romantic organ inspired generations of composers, beginning with César Franck and continuing through the 20th century. In the Romantic era organs began to be built in concert halls, and the organ began to be called for in large symphonic works by such composers as Camille Saint-Saëns and Gustav Mahler.
A major revolution in pipe organ design took place in the late-19th century when the development of pneumatic, electric and electro-pneumatic key actions made it technically feasible to locate the console independently of the pipes. There are however, advantages to more historical mechanical actions. Although they can be heavy to play, they allow a more subtle touch-sensitive feel to playing. Because the keys are physically attached to the valves that allow wind into the pipe, the organist has a greater sense of tactile feedback allowing greater rhythmic control. Also, the organist has more control over the onset of the speech of the pipes. When organ builders began building historically-inspired instruments, they returned to mechanical key action to regain the subtle, nuanced control it gives the performer. Due to the benefits of modern technology, modern mechanical actions are often much lighter and require less effort to play than the original, substantially heavier mechanical actions. During the 20th century, electrically-controlled stop actions allowed for the development of sophisticated combination actions.
Developments in the computer industry began to be incorporated into pipe organs using the techniques developed for pipeless organs (see below), incorporating them as "digital" components into real pipe organs. This had many advantages, such as actions that were much more simple in concept, as well as the allowance of better combination capture systems. This is one of the greatest modern developments to the organ, as it allows the organist to set piston combinations or even a sequencer for each individual piece or occasion, simply by the computer storing combinations drawn at the console. Another development to the organ is the MIDI recording system, which can record and replay what an organist has played, and can even download files of these recordings onto a computer.
Pipeless organs (pseudo-organs)
In the mid-20th century, churches and other institutions began increasingly substituting electronic organs without pipes (such as the Allen organ, or the Rodgers organ) for pipe organs due to the cheaper initial cost. These instruments generally depend either on the Hammond system of generating sound or recorded computer loop sounds. In the later 20th century, digital pipeless instruments were developed that emulate the sound of a pipe organ through digital sampling techniques. Although the entire sound of a pipe organ cannot yet be completely recreated, they are still a viable option to many churches and other organizations, due to the lower costs involved, the lack of maintenance required, and the small amount of space necessary, as opposed to a substantial pipe organ. It is increasingly common for builders of new pipe organs to use digital stops for the very lowest pedal ranks owing to the economy of space and reduction of fabrication cost so enabled. Most organ builders and organists agree, however, that digital 32' ranks are less acceptable than digital pipes of higher pitches. Since the Baroque era and before, 32' ranks have been appreciated for their ability to augment harmonic richness in the rest of the organ while stirring the low frequencies in the air—two effects a speaker is unable to replicate. Organs such as that in Trinity Church in Copley Square, Boston, which have acoustical and digital 32' stops side-by-side, demonstrate the psychoacoustical inadequacies of the digital 32' stop. Major builders of such instruments include the firms of Allen, Rodgers, Johannus, and Phoenix.
The main elements of an organ are the console, the pipes, the stop mechanism and the wind system and associated windchests.
The organ is played from an area called the console (if it is separate from the rest of the case) or keydesk (if it is integrated into the case), which holds the manuals, pedals, and stop controls. Some very large organs, such as the Van Den Heuvel organ at the Church of St Eustache in France, have more than one console, enabling the organ to be played from several locations depending on the nature of the performance.
In organs that use electronic action, the console is often movable. This allows for greater flexibility in placement of the console for various activities. Some organ builders even use ethernet cables to connect the console to the main interface board. Some large organs may also have two consoles: one built into the organ case itself, the other a movable console used for recitals or for church services, to allow the organist to be closer to either choir or congregation.
Controls at the console called stops select which ranks and pipes are used. These controls are generally either draw stops, which engage the stops when pulled out from the console, or stop tabs that rock up and down. Other stop controls include sliding rods and light-up digital buttons.
Different combinations of stops change the timbre of the instrument considerably. The selection of stops is called the registration. On modern organs, the registration can be changed instantaneously with the aid of a combination action, usually featuring pistons. Pistons are buttons that can be pressed by the organist to change registrations; they are generally found between the manuals or above the pedalboard. In the latter case they are called toe studs or toe pistons (as opposed to thumb pistons). Most large organs have both preset and programmable pistons, with some of the couplers repeated for convenience as pistons and toe studs. Programmable pistons allow comprehensive control over changes in registration. These are commonly grouped under the title registration aids. Newer solid state organs have multiple levels of memory, allowing each piston to be programmed more than once. this allows more than one organist to register the stops they want. many newer consoles also feature MIDI, which allows the organist to record performances. It also allows an external keyboard to be plugged in, which assists in tuning, and troubleshooting.
Pipes, Ranks and Stops
Organ pipes are arranged in ranks. A rank is a complete set of pipes of similar timbre tuned to a chromatic scale. The great majority of ranks are mounted vertically, but some ranks may be mounted horizontally, as is the case with trompettes en chamade. At the base of the pipes is a windchest which supplies air (known in the organ world as "wind") to the pipes. The manner in which the wind is admitted to the pipes varies depending on the type of action, but in any case several ranks of pipes may be supplied by a single windchest. A few of the larger pipes may be "off chest" in order to better fit them into the available space or in order to feature them in the façade. There are two main types of pipe used: flue pipes which use Fipples similar to a recorder and reed pipes which contain a beating reed in the manner of an clarinet.
The organ's individual ranks are activated by the organist through the stop mechanism. There are many different varieties of stop mechanisms, some proprietary, but the principal distinction is between mechanical and electric mechanisms. Mechanical stop mechanisms connect the stop controls directly to the windchests through a series of wooden or metal rods. When the organist moves the stop control, the rods move. This actuates the mechanism at the windchest that allows or denies wind to the stop. Electric stop mechanisms control the mechanism at the windchest through electronics, which are activated when the organist moves a stop control at the console.
Once a stop is drawn, there is wind access to the ranks controlled by that stop. Sound is then made by pressing keys down that allows the wind to travel into each individual pipe. When multiple stops are drawn, the depressed key allows air to enter every rank that has been selected.
The choice of stop mechanism depends on the design of the organ and the console. If the console is located farther away from the rest of the organ, a mechanical stop action is harder to implement than when the console and the organ are in closer proximity. The more complicated registration aids, such as thumb and toe pistons, especially those which can be specified to control certain stops require an electrical action, although a rudimentary system is available with a mechanical action.
Pipes may be classified in several ways, each of which results in a different timbre:
- by the material they are made of (wood or metal)
- by the mechanism of sound production (flue pipes vs. reed pipes, also called labial and lingual)
- by the shape of the pipe (cylindrical, conical, or irregular)
- by the construction of the ends (open or closed).
Because a pipe produces only one pitch at a time, ideally there is at least one pipe for each controlling key or pedal, although in some instances, one key may control more than one pipe at a time, such as a mixture, a stop consisting of several ranks of different pitches sounding together. (Occasionally some pipes, especially in the bass, are rigged to provide multiple pitches like big recorders to save space or material: a method employed especially by a few builders in the early 20th century.)
The sound of a pipe can be altered by use of a device called a Tremulant. This fluctuates the air supply going to the pipes giving a tremolo effect.
Flue pipes produce sound the same way as a recorder: they are whistles. The definition of a whistle is a sound producing device in which nothing but air molecules move. The majority of organ pipes are flue pipes and they produce the "foundation" sound of an organ. They are used in single-rank unison and mutation stops as well as multi-rank mixtures.
Mostly, flue pipes belong to one of three tonal families:
- Flutes which have the simplest waveforms, sometimes approaching a sine wave.
- Diapasons or Principals which have a more complex waveform and a tone midway between flutes and strings.
- Strings which have the most complex waveforms.
The width of the pipe affects the tone of the pipe. When comparing pipes of otherwise identical shape and size, a wide pipe will tend to produce a flute tone, a medium pipe a Principal tone, and a narrow pipe a string tone. These relationships are referred to as the scale of the pipe: i.e. wide-scaled, normal-scaled, or narrow-scaled. (see Organ flue pipe scaling)
Ranks of all three tonal families are either "open" or "stopped", although flutes are by far the most common to be stopped. A stopped pipe is closed at one end, meaning the sound travels up and down the length of the pipe. This means that the pipe can be half the length of an open pipe, as the distance traveled by the sound will be the same.
Flue pipes can be made of metal or wood. The cross-section of a metal pipe is usually circular, while the cross-section of a wooden pipe is most commonly square or rectangular.
Metal flues are usually made of varying mixtures of lead and tin, depending on the requirements sought for that particular pipe. The more lead used in the alloy the darker the resulting tone. Conversely, if a pipe has a high proportion of tin, it will have a brighter tone. In addition, high amounts of tin give a gleaming and long-lasting polish which may be required if the pipe is clearly visible. Pure lead or pure tin are both too soft to be used; the best strength ratio is approximately 60% tin to 40% lead. The cost of each metal is also a factor, with tin being of far greater expense than lead. The usual exceptions to tin-lead alloys are very lowest pipes in a rank, which are sometimes made of rolled zinc; however, pipes have been made of many metals, including gold, silver, aluminum, brass, copper, and iron, and, very rarely, glass, porcelain, and plastic.
The walls of a wood flue are made either from a coniferous wood, or of hardwood. The lower section of the pipe (comprising the foot, cap, block and mouthpiece) will nearly always be made from hardwood.
Reed pipes, for example "Clarion" or "Trombone" are more complicated than flues to manufacture, because the sound is produced by a beating reed using the same principle as that of the orchestral clarinet. They are used almost exclusively as single-rank stops adding to the foundation sound, and feature several different shapes of resonators and a great variety in tone color. Reed stops also imitate other historical musical instruments, such as the Crumhorn, and the Regal.
The "reed" is actually made from brass. The sound is created entirely inside the pipe foot (or "boot"), but is amplified and given its respective color by the resonator, which projects upward from the boot. Resonators can be shorter than the corresponding pipe of a flue rank at the same pitch (called "fractional length") or twice as long ("double length"), depending on the tone desired. They can be cylindrical and high in lead content (common in the "clarinet" stop) or conical and high in tin content (common in the "Trompette" stop). In addition, they can be narrowly flared, broadly flared, capped, semi-capped or open. All these variations have an effect on the tone produced.
Reed pipes are physically "stopped pipes"; that is, when the vibrating tongue is pressed against the shallot (mouthpiece), that end of the pipe is stopped. As a result, if the resonator is cylindrical only odd-numbered harmonic partials are heard, for example in the hollow tones of Crumhorns and Clarinets. If the resonator is conical the geometry allows the production of even- and odd-numbered partials, resulting in the 'open' tones of Trumpets and Oboes.
A diaphone is a unique and uncommon organ pipe. Invented by Robert Hope-Jones around 1900, it is neither a flue nor a reed, but has characteristics of both. The pipe speaks through a resonator, like an organ reed pipe, but the tone is created by a pallet instead of a reed. The pipe is generally of wooden construction, although some examples of metal diaphones exist, and can be voiced on various wind pressures.
The diaphone is found mostly at 16' and 32' pitches (see length of pipes), however there are a few examples of 8' diaphones, and a full-length 64' Diaphone-Dulzian is installed in the Boardwalk Hall Organ in Atlantic City (which is one of only two true 64' stops in the world, the other being the Contra Trombone reed stop in the Sydney Town Hall organ).
Hope-Jones also developed an imitative version called a diaphonic horn which had a more reed-like quality and was voiced on lower wind pressures. Wurlitzer built a version for their theatre organs at 16' and 8' pitch, known as a horn diapason.
The Austin Organ Company developed a metal diaphone known as a magnaton, at 16' pitch. Other variants include: diaphone bassoon, contra diaphone, stentor diaphone and diaphonic diapason.
In addition to pipe organs, diaphones have been used as foghorns due to their penetrating tone. The Chance Bros. 'Type G' foghorn at Low Head, Tasmania, is a prime example of this type. In foghorns the sound signal is produced by means of a slotted piston moved back and forth by compressed air. A “two-tone” diaphone produces two sequential tones with the second tone of lower pitch.
Another type of diaphone has been used primarily as a fire signal. This smaller (approximately 30") variant (also known as a 'Type B' or 'Type C') was manufactured by the Gamewell Company of Massachusetts and operates on a reservoir of compressed air combined with a valve or solenoid to create powerful blasts of sound which can be heard over a wide area.
Miscellaneous percussion and effect stops
Some organs feature one or more stops that do not fall into the standard categories or do not have pipes at all. The Zimbelstern (German for "cymbal star"), a revolving star-shaped wheel of bells, is quite common on German Baroque-inspired instruments. The Nightingale stop (Nachtigall in German, Rossignol in French) blows wind through a small pool of water, creating the sound of a bird warbling, and is fairly common on French Classical organs. The Drum typically includes a cymbal and is a feature of eighteenth-century Italian organs. The Chimes, the Celesta, and the Harp are occasionally found on American instruments. Theatre organs usually have a large battery of percussion effects, as well as noise makers that imitate sounds such as helicopters or ocean waves. French romantic instruments such as the Cavaillé-Coll organ in Saint-Sulpice sometimes feature the éffet d'orage (French for "thunder effect," generally called the "thunder pedal") and the Avalanche, used in the performance of storm compositions and improvisations.
Pitch and Temperament
The system used for indicating pitches in this article is the so-called Helmholtz system, in which middle c is c', the octave above c", etc., the octave below middle c is simply c or c0, and the octave below that capital C, then CC, CCC, etc.
- For a general article on musical pitch, see Pitch (music)
For many years, there was no pitch standard across Europe. The pitch of a', for example, could range from A=392 Hz in parts of France to A=465 Hz in parts of Germany.  Organs were often tuned differently than ensembles, even within the same region or town. The modern tuning standard a'=440 Hz (c'=256 Hz) was proposed in 1939, and accepted by the International Organization for Standardization, (as ISO 16) in 1955 (and again in 1975).
Many new chamber organs and harpsichords today feature transposing keyboards, which can slide up or down one or more semitones. This allows these instruments to be played with Baroque instruments at a'=415 Hz, modern instruments at a'=440 Hz, or Renaissance instruments at a'=466 Hz. Organs are now typically tuned in equal temperament, in which every semitone is 100 cents wide, though many organs that are built today following historical models are tuned to historically-appropriate temperaments.
Pitch and lengths of pipes
When considering the labeled lengths of ranks of pipes, the length of a foot is 328 mm when the speed of sound is 343 m/s.
The pitch produced by a pipe is a function of its length. A stop may be tuned to sound (or speak at) the pitch normally associated with the key that is pressed (the written pitch or unison pitch), or it may speak at a fixed interval above or below this pitch. The pitch of a pipe rank is denoted by numbers on the stop knob. A stop tuned to unison pitch is known as an 8' stop ("eight foot"). This refers to the approximate speaking length of the longest open flue pipe of that stop, sounding C (the C two octaves below middle C). It is these 8' stops which sound at the same pitch as a piano. A 4' stop (so called because its C pipe is approximately four feet long) speaks an octave above an 8' stop. Therefore a 2' stop speaks two octaves above, 1' is three octaves above. Consequently a 16' stop speaks one octave below, 32' is two octaves below, and an extremely uncommon 64' stop three octaves below.
A stopped pipe is one in which the top end of the pipe is blocked ("stopped") meaning the air travels up and back down the pipe, doubling the length of the sound column. This means a stopped pipe of 4' length will sound as an 8' stop. This has many space saving advantages as well as varying tone qualities available. This would mean that the longest pipe in an 8' Stopped Diapason is actually only 4' long.
Ranks that are not at a unison pitch (i.e. not 32', 16', 8', 4' etc) are called mutation stops. Because they sound at intervals of a fifth or a third above the unison sound, they are rarely used on their own. If they were, it would change the melody and the harmony of the music played. Instead, that are combined with fundamental stops to create new tone colours.
- A stop at 2 2/3' pitch (called a "Nazard" or a "Twelfth") sounds at an interval of a twelfth (one octave plus a fifth) above unison pitch. (In some historical organs a stop at 2 2/3' pitch is labeled as 3'; this is purely a representation of historical convention and does not indicate that the stop is any different from one labeled 2 2/3'.)
- A "Tierce", 1 3/5' pitch, sounds at an interval of a seventeenth (two octaves plus a third) above unison pitch.
- A mutation stop in the pedal department will usually be a "Quint", 10 2/3', sounding a fifth above a 16' pedal note.
Certain stops called mixtures contain multiple ranks of pipes. The number of ranks in a mixture is denoted by a Roman numeral in the stop name: a stop labeled "Mixture V" on a 61-note keyboard would contain 305 pipes, 5 pipes for every note. This means that for every key pressed, 5 different pipes sound, all activated by the one stop. The multiple ranks in a mixture are usually pitched at intervals in the harmonic series reinforce certain partials of a fundamental, like mutations; however, mixtures are generally used to color the foundation sound as opposed to use in 'solo' combinations. Mixtures are the survival of the old Blockwerk (see above) in which there were no individual stops, but merely the unvarying full ensemble. Thus 'stops' were originally just that, a means of stopping off some ranks of the Blockwerk to enable the use of single ranks of pipes.
See also: List of pipe organ stops
Stop names are not always consistent; indeed many that have identical sounds will vary in name from organ to organ. The choice of the name reflects not only the timbre and construction of the stop, but also the style of the organ in which the stop resides. For example, the stop names on a German Baroque organ will generally be derived from the German nomenclature, while the names of similar stops on an English Romantic organ will be derived from the English tradition. Most countries tend to use only their own languages for stop nomenclature. English-speaking nations are more receptive to foreign nomenclature, as is Japan (necessarily, for it historically had no indigenous organ-building culture).
A traditional stop label includes two parts:
- the name of the stop (Diapason, Rohrflöte, Cornet, Trompette, etc.)
- the pitch (8', 4', etc.), or the number of ranks controlled by the stop (III, VI–VIII, etc.)
Thus, a stop labeled 8' Harmonic Flute is a single-rank flute stop sounding at 8' pitch and one labeled Cornet V is a five-rank mixture (Cornet). Conventionally, a resultant bass (or resultant) stop, which plays two or more ranks in a harmonic series in order to create the illusion of a lower pitch, is labeled only with the resultant tone. For example, the relatively common combination of a 16' rank and a 10 2/3' rank, producing the impression of 32' tone, would be labeled Resultant 32'.
Stop nomenclature was more strictly observed in classic organ building than it is today. Specific variations of stop construction would have specific names. Classically, a "twelfth" and a "nasard" were essentially similar stops, but the terms "twelfth" or "quinte" were used if the pipes were made as diapasons, and the term "nasard" was used if the pipes were made as flutes. Today, a lot of stop names are used interchangeably.
Unification and extension
When a rank of pipes is available as part of more than one stop, the rank is said to be unified, or borrowed. Ranks can be borrowed within a single division or between manuals. For example, an 8' Diapason rank may also be made available as a 4' Octave. When both of these stops are selected and a key (for example, middle C) is pressed, two pipes of the same rank will sound: the middle C pipe and the pipe one octave higher.
Furthermore, if both the middle C key and the C an octave higher are pressed simultaneously, only three pipes will sound. This is because one pipe has been selected twice: once as the 4' Octave of middle C and once as the 8' Diapason of the key an octave higher. This is known as a "borrowing collision", and is one reason that borrowing from a rank is generally regarded as inferior to including a separate rank. Moreover, a dedicated 4' stop would be voiced and scaled slightly differently than the 8' stop; there is no opportunity to do this with a borrowed rank.
Due to the necessities of the technique, unification is difficult to accomplish without electric stop action. It is generally used when funds are scarce, as unifying one rank with another is much cheaper than building two separate ranks. Some organ builders, such as Schoenstien, have been successful (i.e., they have not compromised the unity or the quality of the instrument) in making extensive use of unification in order to allow for unique registrational effects.
When a rank is borrowed, the organist may run out of pipes at one end of the keyboard or the other. In the above example, there are no pipes in the original rank to sound the top octave of the keyboard at 4'. The neatest and most common solution to this is to provide an extra octave of pipes used only for the borrowed 4' stop. The full rank of pipes is now an octave longer than the keyboard, and is called an extended rank or an extension rank. An organ that relies heavily on extension is called an extension organ.
Organization of console controls
In modern organ building, an accepted standardized scheme is used for the layout of the stops and pistons on the console. The stops controlling each division (see Keyboards) are grouped together. Within these, the standard arrangement is for the lowest sounding stops (32' or 16') to be placed at the bottom of the columns, with the higher pitched stops are placed above this, (8', 4', 2 2/3', 2' etc.); the 'mixtures' are placed above this (II, III, V etc). The stops controlling the reed ranks are placed collectively above these in the same order as above, often with the stop engraving in red.
Thus, an example stop configuration for a Great division may look like this:
The standard position for these columns of stops (assuming drawknobs are used) is for the Choir or Positiv division to be on the outside of the players' right, with the Great nearer the center of the console and the music rest. On the left hand side, the Pedal division is on the outside, with the Swell to the inside. Other divisions can be placed on either side, depending on the amount of space available. Manual couplers and octave extensions are placed either within the stop knobs of the divisions that they control, or grouped together above the uppermost manual. The pistons, if present, are placed directly under the manual they control.
In order to be more historically accurate, organs built along historical models will often use older schemes for organizing the keydesk controls.
The organ is played with at least one keyboard, with configurations featuring from two to five keyboards being the most common. A keyboard to be played by the hands is called a manual (from the Latin manus, "hand"); an organ with four keyboards is said to have four manuals. Most organs also have a pedalboard, a large keyboard to be played by the feet.
The collection of ranks controlled by a particular manual is called a division. The names of the divisions of the organ vary geographically and stylistically. Common names for divisions are:
- Great, Swell, Choir, Solo, Orchestral, Echo, Antiphonal (America)
- Hauptwerk, Rückpositiv, Oberwerk, Brustwerk, Schwellwerk (Germany)
- Grand Choeur, Grand Orgue, Récit, Positif, Bombarde (France)
- Hoofdwerk, Rugwerk, Bovenwerk, Borstwerk, Zwelwerk (Holland)
In English, the main manual (the bottom manual on two-manual instruments or the middle manual on three-manual instruments) is traditionally called the Great, and the upper manual is called the Swell. If there is a third manual, it is called the Choir and placed below the Great. If it is included, the Solo manual is usually placed above the Swell. Some larger organs contain an Echo or Antiphonal division, usually controlled by a manual placed above the Solo. German and English organs generally use the same configuration of manuals as American organs. On French instruments, the main manual (the Grand Orgue) is at the bottom, with the Positif and the Récit above it. If there are more manuals, the Bombarde is usually above the Récit and the Grand Choeur is below the Grand Orgue.
In addition to names, the manuals may be numbered with Roman numerals, starting from the bottom. Organists will frequently mark a part in their music with the number of the manual they intend to play it on, and this is sometimes seen in the original composition, typically in pieces written when organs were smaller and only had two or three manuals. It is also common to see super- and sub-couplers labeled as "II to I" (see Couplers below)
In some cases, an organ contains more divisions than it does manuals. In these cases, the extra divisions are called floating divisions and are played by coupling them to another manual. Usually this is the case with Echo/Antiphonal and Orchestral divisions, and sometimes it is seen with Solo and Bombarde divisions.
Although manuals are almost always horizontal, organs with five or more manuals may incline the uppermost manuals towards the organist to make them easier to reach.
Enclosure and 'Swell pedals'
On most organs, at least one division will be enclosed. On a two-manual (Great and Swell) organ, this will be the Swell division (from whence the name comes); on larger organs often part, or all of, the choir and solo divisions will be enclosed as well.
Enclosure is the term for the device that allows volume control (crescendo and diminuendo) for a manual without the addition or subtraction of stops. All the pipes for the division are surrounded by a box-like structure (often simply called the Swell box). One side of the box, usually that facing the console or the listener, will be constructed from horizontal palettes (wooden flaps) which can be opened or closed from the console. This works in a similar fashion to a Venetian blind. When the box is 'open' it allows more sound to be heard than if it were 'closed'.
The device at the console that controls the opening or closing or the shutters is commonly called an expression pedal or swell pedal, regardless of the division it operates. The system generally requires one pedal per enclosed division. The pedals are placed in the centre of the console, just above the pedalboard. It usually rotates towards and away from the organist, rotating from an almost vertical position ('shut') to a near horizontal position ('open'). Because the pedal is balanced, the organist does not need to hold it in position, and it will balance at any point in its travel.
In addition, an organ may have a similar-looking crescendo pedal, which would be found to the right of any swell pedals. Applying the crescendo pedal will incrementally turn on all the stops in the organ, starting with the softest and ending with the loudest stops. As the order the stops are activated is chosen by the organ's designers, this is a quick way for the organist to get to a registration that will sound attractive at a given volume without choosing a particular registration, or to simply get to full organ. (Some organs also have a piston that activates full organ.)
A version of the swell pedal found on older organs is the ratchet swell, a lever operated by the foot to the side of the console that will fit into two or three different notches that lock the position of the lever, and therefore the shutters, in place. To alter this, the lever must be kicked sideways to allow it to travel into a new position. The lever is weighted so that its default position is at the top and the shutters are closed. The lower the lever, the more 'open' the swell. Many ratchet swell devices were replaced by the more common balanced swell pedal (above), because it allows the varying degree to be fixed at any point. Also, the location for most swell pedals, above the middle of the pedalboard, is much more convenient for use by both feet as necessary, although it is the right foot that controls it as a general rule.
Correspondence to The Musical Times in 1916 debates the merits of both the level and balanced swell systems. One writer suggests that balanced swell pedals are never satisfactory and are either too sensitive or not sensitive enough [admittedly that was in 1916, and many improvements have been made since], and that he knows many organists were having balanced swell pedals removed. One organist most open to the change suggests that real crescendos and diminuendos are not possible with a lever or lever-ratchet swell as the steps (notches) provided are always either just under or above what is required. The balanced swell pedal does afford the ease of use of either foot as mentioned above, whereas the previous correspondent wished for two ratchet levers, one either side of the pedalboard. 
A device called a coupler allows the pipes of one division to be played by a manual. For example, a coupler labeled "Swell to Great" allows the stops of the Swell division to be played by the Great manual. It is unnecessary to couple the pipes of a division to the manual of the same name (for example, coupling the Great division to the Great manual), because those stops play by default on that manual (though this is done with super- and sub-couplers, see below). By using the couplers, the entire resources of an organ can be played simultaneously from one manual. On a mechanical-action organ, a coupler may connect one division's manual directly to the other, actually moving the keys of the first manual when the second is played.
Some organs feature super-couplers and sub-couplers, which shift the connection of the coupler respectively up or down by an octave. Super-couplers are usually labeled with the suffix "4'" or "octave", as in "Swell to Great Octave", and sub-couplers with the suffix "16'" or "sub-octave", as in "Swell to Great 16'". The inclusion of these couplers allows for greater registrational flexibility and color. Some literature (particularly romantic literature from France) calls explicitly for octaves aigues (super-couplers) to add brightness, or octaves graves (sub-couplers) to add gravity. Some organs feature extended ranks to accommodate the top and bottom octaves when the super- and sub-couplers are engaged (see the discussion under "Unification and extension").
Some organs also have super-octave and sub-octave stops. These cause pipes an octave higher or lower to be sounded respectively. This is is useful in conjunction with a super- or sub-coupler. Closely related are unison off couplers, which act to "turn off" the stops of a division on its own keyboard. For example, a coupler labeled "Great unison off" would keep the stops of the Great division from sounding, even if they were pulled. Unison off couplers can be used in combination with super- and sub-couplers to create complex registrations that would otherwise not be possible. In addition, the unison off couplers can be used with the standard couplers to change the order of the manuals at the console: engaging the Great to Choir and Choir to Great couplers along with the Great unison off and Choir unison off couplers would have the effect of moving the Great to the bottom manual and the Choir to the middle manual.
Another form of coupler found on some large cathedral organs is the divided pedal. This is a device that allows the sounds played on the pedals to be split, so the lower half (principally that of the left foot) plays the Pedal stops, whereas the notes the right foot plays (simultaneously) are stops from one of the manuals. The choice of manual, i.e. whether, for example the Great, Swell or Solo etc, is at the disposal of the performer, as is the split point of the system.
The system can be found on both Gloucester Cathedral and Truro Cathedral having been added by David Briggs, and most recently was added to the new nave console of Ripon Cathedral. The system as found in Truro Cathedral operates like this:
- Divided Pedal (adjustable dividing point): A# B C C# D D#
- under the 'divide': Pedal stops and couplers
- above the 'divide': four illuminated controls: Choir/Swell/Great/Solo to Pedal
This allows four different sounds to be controlled at once, for example
- R.H. - Gt Principals 8' and 4'
- L.H. - Sw Strings
- Left Foot - Pedal 16' and 8' and Sw to Pedal coupler
- Right Foot - Solo Clarinet via Divided Pedal coupler
In order for an organ to sound, it is necessary for air to be directed through the pipes. The air, referred to as wind in the organ trade, is generated in one of three ways:
- The organ is pumped by hand. When signalled by the organist (often by a small bell), a calcant (the blower operator) pumps the bellows of the organ by any of several mechanisms, supplying them with air. Before the advent of electricity, this is how all organs were provided with wind. Playing the organ in those days required at least one person to work the bellows. Compensating calcants was expensive. Thus, practicing was usually not done on the organ, but on smaller instruments such as the clavichord or harpsichord. A few organs that can be pumped by hand still exist, and modern instruments have been built with this capability.
- The organ is pumped by foot pedals. The organ lacks a pedalboard, and instead is equipped with two foot pedals, which are alternately pressed down by the organist to keep a constant flow of air. This has the advantage to the player of not requiring an assistant. However, long or repeated performances can be very tiring on the organist if they are not used to it, and it also requires some coordination, as the tempo of the piece might not match the tempo which the pedals require. This system is predominantly found on a Harmonium (a free reed keyboard instrument).
- An electric blower fills the bellows with air. Once electricity made the electric blower a reality, every new organ made use of it and virtually every old organ was outfitted with one. Suddenly, it became possible for organists to practise regularly on the organ. Before the advent of electric blowers it is thought that some organs were fitted with motors (often water turbines) which manipulated the bellows through the use of a crankshaft.
Once the wind is produced through one of these three means, it is stored in one or more reservoirs of varying designs. The reservoirs are weighted and/or sprung to produce a constant wind pressure (in inches, as measured with a water tube manometer), which differs with the design of the organ and the division the wind supplies. An Italian organ from the Renaissance may feature a wind pressure of only 1.5 inches, while an orchestral organ from the early 20th century may have wind pressures as high as 25 inches in some divisions. At the Boardwalk Hall Organ, there is a reed stop, the Ophicleide, on 100 inches of wind. This stop is listed in the Guinness Book of Records as the loudest in existence (the book described it as a pure trumpet note of ear-splitting volume, more than six times louder than the loudest locomotive whistles).
The wind flows from the bellows through one or more large pipes known as wind trunks to the separate divisions of the organ. There, the wind is fed into the windchest, which is directly under the pipes. Then, through the key action, the wind flows into the pipes and the pipes speak.
The above elements of most organs are housed in a free-standing organ case or a dedicated room called an organ chamber. Of the two, the free-standing case is considered by most organists to be acoustically superior and was the style preferred by the great organ builders of the Renaissance and Baroque periods. During the latter 19th century the shift to chambers began—followed shortly by electro-pneumatic action—and by the mid 20th century some organists (notably E. Power Biggs) were pleading for a return to the old construction methods (i.e., tracker action organs in free standing cases).
In either type of contruction, the pipes are separated from the listeners by a grill that often contains decorative pipes known as a façade. Some organs do not have any discernible pipe façade (this is, in fact, a type of case design in itself), or they may have a screen behind which all of the organ's pipes are hidden.
In some organs with façade pipes, especially those which are based on historical styles from the time before the 20th century, the façade pipes are genuine, speaking pipes. They usually form part of an open flue rank from the Pedal or Great division, most of the time, the Principal stop. In other organs, the façade pipes are purely decorative and non-speaking.
Even with non-speaking pipes, the façade is considered an important part of an organ, much as the scroll of a violin is considered a part of that instrument. The façade also serves an acoustic function, changing the tone of the organ as the sound waves travel through it, as well as a means of masking swell boxes located behind it.
Organ music and composers
See the main articles: organ repertoire, organ tablature and List of organ composers.
Organ music is generally written on three staves (one for each hand, and one for the pedals), but can be up to five staves in more complicated music. Some music is written with two staves, with the pedal notes written on the bottom staff as a divisi part. (See BWV 565 for an example.)
There is a large repertoire of both secular and sacred music for the pipe organ, the majority of which comes from the Renaissance, Baroque and Romantic periods.
The most famous composer of organ music was Johann Sebastian Bach, who composed substantial solo music for the organ and arranged music by other composers for the organ. Bach's output of organ music during his lifetime was extensive, and there are many 'complete' editions of his works that can stretch to over 20 volumes (depending on how the pieces are sorted).
The Baroque period is well represented by other German composers such as Dietrich Buxtehude, Johann Jakob Froberger and Johann Pachelbel. French organ music developed under the Baroque (French Classical) period by François Couperin and Louis-Claude Daquin. Organ music really developed in the Romantic period by French organists/composers, many of whom are almost exclusively know for their organ repertoire, for example César Franck, Charles-Marie Widor, and Olivier Messiaen, Louis Vierne and Charles Tournemire. German composers like Felix Mendelssohn, Max Reger and Josef Rheinberger also developed a symphonic style. In fact, it was Mendelssohn's virtuoso organ playing that brought Bach back from obscurity following his death in 1750.
The organ has been integrated into many symphonic compositions and concertos, perhaps most famously in Camille Saint-Saëns Organ symphony, Joseph Jongen's "Symphonie Concertante for Organ & Orchestra", and Francois Poulenc's "Concerto for Organ, Strings and Tympani". The earliest organ concertos in the form we recognise today are by George Frederick Handel. Other composers who used the organ in some of their orchestral music are Gustav Holst, Béla Bartók, Richard Strauss, Ottorino Respighi, Gustav Mahler, Pyotr Ilyich Tchaikovsky, Franz Liszt, Charles Ives, Anton Bruckner and Ralph Vaughan Williams to name just a few.
Although most countries whose music falls into the Western tradition have contributed works to the pipe organ's repertoire, France and North Germany are particularly notable for having produced many exceptional composers for the instrument. There is also extensive repertoire from the Low Countries, England and the United States.
The development of the repertoire has gone hand in hand with the development of the instrument, leading to distinctive national styles of composition; in the opposite direction, the dominance of certain countries in providing the repertoire has influenced the emergence of an international mainstream of organ design. Thus the repertoire of Spain, Portugal and Italy is rarely heard outside those countries, because the tonal styles of their organs are quite distinct from the German-French-British-American mainstream. Likewise, there is little Russian or Greek organ music because those nations' Orthodox churches do not use the organ in worship.
- In this paragraph references to "pipe organ" may refer to pipeless imitative or synthesized instruments.
Church-style pipe organs are very rarely used in popular music. In some cases, groups have sought out the sound of the pipe organ, such as Tangerine Dream, which combined the distinctive sounds of electronic synthesizers and pipe organs when it recorded both music albums and videos in several cathedrals in Europe. Rick Wakeman of British progressive rock group Yes also used pipe organ to excellent effect in a number of the group's albums (including "Close To The Edge" and "Going For The One"). Wakeman has also used pipe organ in his solo pieces such as "Jane Seymour" from The Six Wives Of Henry VIII and "Judas Iscariot" from Criminal Record. Even more recently, he has recorded an entire album of organ pieces - "Rick Wakeman at Lincoln Cathedral". George Duke employed the pipe organ in a flamboyant manner in the piece "50/50" on the Frank Zappa album Over-Nite Sensation.
On the other hand, electronic organs and electromechanical organs such as the Hammond organ have an established role in a number of non-"Classical" genres, such as blues, jazz, gospel, and 1960s and 1970s rock music. Electronic and electromechanical organs were originally designed as lower-cost substitutes for pipe organs. Despite this intended role as a sacred music instrument, electronic and electromechanical organs' distinctive tone-often modified with electronic effects such as vibrato, rotating Leslie speakers, and overdrive-became an important part of the sound of popular music. Billy Preston and Iron Butterfly's Doug Ingle have featured organ on popular recordings such as "Let it Be" and "In-A-Gadda-Da-Vida", respectively. Well-known rock bands using the Hammond organ include Pink Floyd and Deep Purple, and more recently The Arcade Fire.
Recent performers of Popular organ music include William Rowland of Broken Arrow, Oklahoma who is noted for his compositions of "Piano Rags" which he plays on a Wurlitzer theatre organ in Miami, Oklahoma; George Wright (1920-1998) whose "Jealousie" and "Puttin on the Ritz" are some of the finest performances of this genre and Virgil Fox (1912-1980), who bridged both the classical and religious areas of music with pop and so-called Heavy Organ concerts that he played on an electronic organ accompanied by a light show similar to those created in the 60's for rock concerts.
The American Theatre Organ Society ATOS has been instrumental in programs to preserve the instruments originally installed in theatres for accompaniment of silent movies. In addition to local chapter events they hold an annual convention each year, highlighting performers and instruments in a specific locale. These instruments feature the Tibia pipe family as their foundation stops and regular use of tremulants. They were usually equipped with mechanical percussion accessories, pianos, and other imitative sounds useful in creating movie sound accompaniments such as auto horns, doorbells, and bird whistles.
Some notable pipe organs
- The world's oldest playable pipe organ is located in the Basilica of Valère in Sion, Switzerland. Built around 1435, most of the case is original, but only 12 pipes are original, as these have been replaced during restorations. 
- The largest operational pipe organ, with 28,482 pipes and 461 ranks, is the Wanamaker Grand Court Organ in Philadelphia. It is also the second largest organ yet built and the largest functional musical instrument in the world. It is played twice a day, six days a week, and there are many recordings of this organ.
- The Bamboo Organ at St. Joseph's Church in Los Piñas, Philippines. It was built in the early 1800s by a Spanish Priest entirely of Bamboo. It is the site of The World International Organ Festival held once a year. Recordings exist and are available online from St. Joseph's Church. Search for 'bamboo organ'.
- The largest pipe organ ever built, containing more than 32,000 pipes, is the Boardwalk Hall Organ in Atlantic City, New Jersey, built by the Midmer-Losh Organ Company between 1929 and 1932. It contains the worlds largest and only 64' Diaphone, the 64' Diaphone-Dulzian in the Pedal Right Division. Today, the instrument is being restored, with a $1.17 million grant from the New Jersey Sports and Exposition Authority, to return the Right Stage Chamber of the Midmer-Losh organ and the entire ballroom Kimball organ to playable condition. The five-manual portable console will also be restored with new digital technology which will allow full interface with the Midmer-Losh organ.
- The Grand Organ in the Sydney Town Hall's Centenary Hall, Australia was for many years the largest in the world. It remains the world's largest organ without any electric action components and is one of only two organs with a full length 64'stop - the Contra Trombone . The Contra Trombone can be heard by referring to http://www.sydneyorgan.com/STH64.mp3.
- The world's largest all pipe church organ, with about 21,800 pipes and some 355 ranks, is at the Cadet Chapel, United States Military Academy, West Point, New York. (Details: 380 ranks, 874 stops, 293 voices, 23 divisions (across 4 manuals), 23,500 pipes. Stoplist). It is continually being enlarged.
- The world's second largest church pipe organ, with some 20,000 pipes and 345 ranks, is at First Congregational Church, Los Angeles. Details and Stoplist.
- The Ontario Science Centre's main exhibit is a Hydraulophone, a kind of water-jet organ. This pipe organ has hydraulic action provided by three water pumps and the keys on the organ console are water jets, so that each "key" (water jet) affords a richly intricate means way to independently control volume, pitch, and timbre affecting each of the organ pipes. See Opening and Lesson (how to play it).
- The Sydney Opera House organ is the largest organ (200 ranks, 130 voices, 5 manuals, 10,154 pipes) with mechanical key action.
- The Royal Albert Hall Organ is the largest pipe organ in the United Kingdom.
- The world's largest house organ can be found in the United States, in the Barry Norris Residence, Birmingham, Alabama. It has 200 ranks, 161 voices and a total of 11,200 pipes, which can be played from the five-manual console in the living room.
- For a list of notable pipe organ builders, see Category:Pipe organ builders.
- For a list of notable pipe organists, see List of organists.
- ^ http://www.timesonline.co.uk/article/0,,2-2091757,00.html
- ^ http://www.answers.com/topic/pull-out-all-the-stops
- ^ http://www.concertartist.info/organhistory/begin.htm
- ^ http://www.lawrencephelps.com/Documents/Articles/Beginner/pipeorgans101.html
- ^ http://www.concertartist.info/organhistory/begin.htm
- ^ http://www.cummingfirst.com/organ.html contains information on the Hydraulis
- ^ http://www.archaeologychannel.org/hydraulisint.html contains information on the Hydraulis
- ^ http://www.concertartist.info/organhistory/begin.htm
- ^ For a reproduction see J. F. Riaño, Studies of Early Spanish Music, pp. 119-127 (London, 1887)
- ^ http://www.lawrencephelps.com/Documents/Articles/Phelps/abrieflook.shtml
- ^ www.synec-doc.be/musique/dbedos/dbedos.htm Extracts in French, translated into English as Ferguson, Charles (trans.), (1977) The Organ-Builder. Translation of Dom François Bedos de Celles l'Art du Facteur d'Orgue 1766-68. Sunbury Press, Raleigh, NC
- ^ http://www.rosskingco.com/Pages/ref_mechanism.htm
- ^ http://www.trinitychurchboston.org/music/organ-specs.pdf specification of Trinity Church, Boston organ
- ^ www.music.vt.edu/musicdictionary/appendix/octaveregisters/octaveregisters.html
- ^ http://www.polettipiano.com/Media/pitch.PDF#search=%22Baroque%20musical%20pitch%22
- ^ http://bach.tuning.googlepages.com/organtuning
- ^ http://www.dolmetsch.com/musictheory27.htm
- ^ http://www.wam.hr/Arhiva/US/Cavanagh_440Hz.pdf
- ^ http://www.jstor.org/view/00274666/ap030169/03a00120/0
- ^ http://npor.emma.cam.ac.uk/cgi-bin/Rsearch.cgi?Fn=Rsearch&rec_index=N11147
- ^ http://www.nzorgan.com/vandr/blowers2.htm Article on Organ blowers
- ^ http://pipedreams.publicradio.org/articles/0503_what_to_play.shtml
- ^ http://www.die-orgelseite.de/kurioses_e.htm
- ^ http://www.ohta.org.au/Sydney_conf/SYDNEYTOWNHALL.html
- Sumner, William Leslie. "The Organ: Its Evolution, Principles of Construction and Use." ISBN 0-7812-0572-7
- Williams, Peter. "The European Organ, 1458–1850." The Organ Literature Foundation. Nashua, New Hampshire, 1966.
- Owen, Barbara. "The Mormon Tabernacle Organ: An American Classic" Church of Jesus Christ of Latter-day Saints (1990) ISBN 1-55517-054-4
- OHS Pipe Organ Database
- The Top 20 - The World's Largest Pipe Organs
- The Pipe Organ
- Worlds Largest Pipe Organs (ranked by number of ranks - site is outdated)
- United States Pipe Organ Directory
- National Pipe Organ Register (NPOR) - Database and specification of every pipe organ in the United Kingdom
- A Young Person's Guide to the Pipe Organ
- Encyclopedia of Organ Stops over 2500 stop names, with pictures and sound clips.
- Pipe Organ Wiki
- The world's largest organs with photos and stoplists...
- Pipedreams Listen to hundreds of hours of pipe organ music online
- Bach's Organ Tuning
- Flue Pipe Acoustics
- Large gallery with pipe organ pictures (German)
- A searchable database of North American Organs
- R.A. Colby, Builders of the Naval Acadamy console.