Pipe organ

From Academic Kids

Missing image
The Casavant pipe organ at Notre-Dame de Montr顬 Basilica, Montreal. Most of the pipes are behind volume-regulating shutters hidden by the visible pipes. Many large installations will have a secondary set of pipes in the choir loft, at the opposite end of the interior space. It is also common for the visible pipes of an organ to be purely decorative, with the real pipes behind them.

A pipe organ is a keyboard instrument that makes its sound by forcing air through wood or metal pipes.

Pipe organs range in size from portable instruments having only a few dozen pipes to grand organs having tens of thousands. All but the smallest have more than one keyboard, with the most common configuration being two manuals played by the hands plus a pedalboard. Three, four or five manuals plus pedals is not uncommon for a larger instrument.

Pipe organs are most commonly found in churches, and in some reformed synagogues. They are also found in town halls, and in arts centres intended for the performance of classical music. In the era of silent films, large pipe organs were installed in many cinemas.


Styles of pipe organ

A more detailed article is to be written at styles of pipe organ.

During its history, several distinctive styles of pipe organ have been developed and achieved popularity at particular times and places, for example the baroque organ, the English romantic organ, the French classical organ, the symphonic organ and the theatre organ.

Even after their period of popularity, instruments of each popular style have continued to be constructed. Each style has its own music (see organ repertoire) which is most authentically played on an instrument of that style, so for example the baroque organ is particularly favoured for playing Bach. So, for example, the Sydney Opera House Grand Organ, whose construction started in 1969 and was completed in 1979, is a baroque style organ.

Not all pipe organs can be assigned to a particular style. Larger instruments may combine several styles in an attempt to provide authentic voices for an extended repertoire, and each one of these instruments is unique. Smaller instruments often combine elements of several styles as a compromise, and so do not fit comfortably into any of them.

Even when an organ is initially built to a particular style, if at a later time it is extended, often the fashion has changed, and the style becomes a compromise. Such extensions are often criticised by organ enthusiasts as unsympathetic to the original style.



The word organ originates from the Latin word "organum", the earliest predecessor of the instrument used in ancient Roman circus games and similar to a modern portative.

Missing image
Among the music-making angels accompanying Domenico di Bartolo's Madonna of Humility, Siena 1433, the angel on the right plays a portatif with a hand-pumped bellows

Pipe organs date back to classical antiquity. Early organs were often hydraulic; the inventor most often credited is Ctesibius of Alexandria, an engineer of the 3rd century BC, who created an instrument called the hydraulis. The hydraulis was common in the Roman Empire, and was capable of being immensely loud; this instrument was used in games, circuses, amphitheatres, and processions. Characteristics of this instrument have been inferred from mosaics, paintings, literary references and partial remains, but knowledge of details of its construction remain sketchy, and almost nothing is known of the actual music it played. In archaeological excavations near Budapest in Hungary (the ancient Pannonia) a Roman organ from the 3rd century AD was found.

 painted  at a "portatif" organ, 1671
Carlo Dolci painted Saint Cecilia at a "portatif" organ, 1671

Organs were also known to exist in Byzantine times, as well as in Islamic Spain, though there is no evidence that the European organ came by way of Spain. In medieval times, the portable ("portatif" or "portative") instruments were invented, and these were used for accompaniment for both sacred and secular music, in a variety of settings--since unlike other organs, they were easily moved.

True pipe organs

As the instruments became larger, they were installed permanently in a fashion similar to the church organs of today. (These were called "positif" organs; today the word tends to label a division.)

Organs were the first keyboard instruments, even though technically they belong to the most complex products of human craftmanship one can possibly imagine.

Recent developments

A major revolution in pipe organ design took place in the 19th century when electric and electro-pneumatic actions made it technically feasible to locate the console independently of the pipes. A later development threatened the very existence of the pipe organ as an instrument, when fully electronic pipeless organs were developed that could fill similar musical roles, see organ (music). However, while both of these developments have made inroads into keyboard music, interest in both pipe organs and even in mechanical actions remains strong, and new instruments with both mechanical and indirect actions continue to be built.

Although the organ's sound has become associated with religious music, having been established in churches and cathedrals for hundreds of years, many major concert halls around the world boast organs. Saint-Sa뮳' popular Organ Symphony is a good example of how the sound of a large organ can be effectively combined with that of a symphony orchestra.


The main elements of a pipe organ are the pipes, the console, and the blower which supplies the air to operate the instrument.


Organ pipes are arranged in ranks. A rank of pipes contains a set of pipes of a similar tone tuned to a chromatic scale. Most pipes are vertical, but a few ranks may consist of horizontal pipes. At the base of the vertical pipes is a wind chest which supplies air to the pipes. The manner in which the air is controlled varies depending on the type of action, but in any case several ranks of pipes may be supplied by a single wind chest. A few of the larger pipes may be off chest in order to better fit them into the available space.

On most organs the pipes are grouped into divisions. For example, on many organs there is a group of pipes operated by the manual second closest to the player, and all of these pipes are contained in a chamber called a swell box which has louvred shutters to control the volume of the sound. These pipes and the keyboard which controls them are called the swell division or swell organ.

Pipes may be classified 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, and by the construction of the ends (open or closed). Each variation results in a different timbre.

Because a pipe produces only one pitch at a time, ideally there is at least one pipe for each controlling key or pedal. (Occasionally some pipes, especially in the bass, to save space or material, are rigged to provide multiple pitches like big recorders: this method was employed especially by a few builders in the early 20th century.) Thus, a keyboard with 61 notes should have 61 pipes, or in some American organs, the keyboards, also called manuals have 58 notes, meaning that there are 58 pipes in the rank. A complete set of pipes producing different pitches of one timbre is called a rank.

The pitch produced is a function of the length of the pipe, and many timbres are associated with ranks pitched some multiple of octaves apart: thus an organ stop may have similar names with the addition of a length in feet indicating the pitch: a 16' stop produces pitches an octave below that of an 8' stop, an 8' stop produces pitches an octave below that of an 4' stop, and a 4' stop produces pitches an octave below that of an 2' stop. Non-integral lengths (e.g. 2 2/3') are also quite widespread; these mutations produce sounds at pitch intervals other than octaves, and are generally used to provide colourful effects. This works by reinforcing certain partials of the overtone series of a fundamental; normally these mutation stops would not be played by themselves.

Some timbres require more than one pipe per key. This is often reflected in the name given to the stop as a Roman numeral: thus a stop called "Cornet V" on a 61 note manual (this is the usual number on U.S. organs) would have 5 × 61 = 305 pipes.

In some organs the extreme bass stops in the pedal department, usually represented by 32' or 64', may not contain "genuine" sounding pipes. This is usually for practical reasons such as cost or space, which may prohibit the provision of very large pipes. In such cases the sound is approximated by using harmonics. For example, a note on a 32' stop can be approximated by combining the equivalent 16' note with the note a fifth above it (known as a "quint"). The resultant beat frequency gives a reasonable impression of a 32' note. This method is less effective (and less necessary) on higher pitches where the ear's frequency response is better. Some of the newest pipe organs substitute electronic subwoofers for the lowest bass notes for the same reasons.

A rank is a set of pipes tuned to a scale, with one pipe per note. Thus a stop may consist of one or more ranks. A stop consisting of more than one rank is termed a mixture, and the number of ranks is commonly indicated by a roman numeral following the stop name, for example a Cornopean IV is a mixture consisting of four ranks of reed pipes.


A stop may be tuned to sound (or speak at) the pitch normally associated with the key that is pressed (the written pitch), or it may be pitched at a fixed interval above or below this pitch. A stop pitched at the written pitch is known as an 8' stop, pronounced eight foot. A stop an octave above is termed 4', an octave below is 16', and so on, the footage being the approximate length of an open flute pipe sounding a C two octaves below middle C at that pitch. An organ foot is 328 mm when the speed of sound is 343 m/s.

Thus, the pitches which sound the octaves above and below written pitch (and therefore have the same note name) are the powers of two: 1' is three octaves above, 2' two octaves above, 4' one octave above, 8' written pitch or unison, 16' one octave below, 32' two octaves below, and 64' three octaves below.

Pitches which are not powers of two are at some other interval, and are called mutation stops. There is no standard naming of these, for example 3' and 2 2/3' are both used to describe a stop sounding an interval of a twelfth above written pitch.

Flue stops, reed stops, and others

Nearly all stops (there are however notable exceptions) fall into one of two types:

  • Flue stops. The pipes of a flue stop are actuated by a whistle or fipple. Most of the pipes of a pipe organ are flue pipes. Diapason (see below) stops are nearly always single ranks of flue pipes, as are most single rank mutation stops.
  • Reed stops. The pipes of a reed stop are actuated by a beating reed. Reed pipes are used both for single rank stops, and for mixtures.

Flue pipes may be subdivided into types in several ways.

Flutes, strings and others

Most (not all) flue pipes are of one of three tone families:

  • Flutes have the purest waveforms.
  • Diapasons or principals have the strongest sounds, and are midway between flutes and strings in tone.
  • Strings have the richest harmonics, and the pipes of these stops tend to be narrower to produce this effect.

Ranks of all three tone families may be either stopped or open, and made either of metal or of wood. Metal pipes are normally round in cross section, while wooden pipes are most often square. Originally this was for ease of manufacture, more recently it is also for reasons of tradition.

Unfortunately, the above terms are far from standardised. Some builders, for example, use the term flute to mean a stopped flute or diapason, and/or the term diapason to mean an open diapason.

The most common flue stop not of any of these families is the [[rohrfl?], see below.

Naming of stops

Missing image
Stops of the baroque Gabler organ in Weingarten, Germany

Many stops have more than one name. The choice of the name reflects not only the tone of the stop, but also the style of the particular organ, for example a baroque organ will generally have its stop names derived from the German, while an english romantic organ will have the names of similar stops derived from the traditions of its style.

The traditional label of a stop has three parts. Firstly, the pitch is given, for example 8'. Then the stop name, for example Cornet, and finally the number of sounding pipes per note, equal to the number of ranks of pipes, for example V. Thus, a stop labelled 8' Cornet V is a five-rank mixture sounding at written pitch. If there is only one rank, the 'I' is normally omitted, as in 16' Bourdon, which would describe a single rank stopped flute sounding one octave below written pitch.

See list of pipe organ stops for some of the more common names.

Borrowing and extension

When a rank of pipes is available as part of more than one stop, this is called borrowing.

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 is pressed, say middle C, two pipes in the same rank will sound, the middle C pipe and the pipe one octave above it.

However, if both middle C and the key an octave above it are pressed at once, only three pipes will sound, as one has been selected twice, once as the octave of middle C and once as the diapason of the key an octave above it. This is known as a borrowing collision, and is one reason that borrowing a rank is regarded as inferior to having a dedicated rank. The other is that a dedicated 4' stop would be designed and voiced slightly differently; There is of course no opportunity to do this with a borrowed rank.

Ranks can be borrowed within a single manual or division of an organ, or between manuals.

When a rank is borrowed, it may not exactly fit the keyboard. In the example above of an 8' diapason borrowed as a 4' octave, 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 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.


The manuals, pedals and stop controls are gathered together in an area called the console. A few very large organs have more than one console, enabling the organ to be played from several locations depending on the nature of the performance.

Controls on the console of the organ called stops select which pipes are used; different combinations of stops can change the timbre of the instrument considerably. The selection of stops is called the registration and can be rapidly changed by use of thumbstops or pistons. Thumbstops are buttons between the manuals, pistons include these and also large pedal buttons (toestuds) operated by the feet. Pistons can either be preset or programmable, with most large organs having both types, and repeating some of the thumbstops and couplers as pedals. Programmable pistons allow comprehensive control over changes in registration.

In those organs that use an electronic action, the console is sometimes moveable. This allows for greater flexibility in placement of the console for various activities. For example, the console at St. Raphael's Cathedral, Dubuque, Iowa is moveable. The console - which is based upon electronic action - is located near the front of the church. Most of the chambers are located in the former choir loft. There is also a small chamber at the front of church along the southern wall. Normally the console is positioned so that it is next to the wall, with the organist seated so his back is to the wall. For recitals the console is often moved so that it is easier for the auidence to see.

The organ console at , , .
The organ console at St. Raphael's Cathedral, Dubuque, Iowa.
Missing image
The four-manual organ console in St. Mary Redcliffe church, Bristol, England. The organist plays the extreme bass notes by pressing the pedals on the floor with the feet. The organ was built by Harrison and Harrison in 1912 and restored in 1990.


The pipe organ has at least one keyboard, with 2-5 keyboards being the most common configuration. A keyboard to be played by the hands is called a manual(because it is played with the hands), so that an organ with four keyboards is said to have four manuals. Most pipe organs also have a pedalboard, a large keyboard to be played by the feet and often just called the pedals.

The pipes controlled by a keyboard are called a department. While in smaller organs pipes are sometimes shared or borrowed between departments, in larger and finer organs this is avoided.

The names of organ departments vary, common names for manuals are Choir, Great, Swell (English); Hauptwerk, Brustwerk, Oberwerk, Schwellwerk, R?itiv (German); Grand Orgue, R飩t, Positif (French). Other names include Solo, Fanfare, Echo, Antiphonal, Orchestral and Bombarde.

In English, the main manual is traditionally called the Great. This is the bottom manual on two-manual instruments or the middle manual on three-manual instruments. The upper manual is called the Swell. If there is a third manual, it is called the Choir and placed below the great. The German equivalents of these three names are: Hauptwerk, Oberwerk and Positiv respectively. Even in English-speaking countries, the German names are sometimes used, depending on the style of the organ.


A device called a coupler connects a division with a keyboard. For example, a swell to great coupler connects the swell organ to the great manual.

On a mechanical-action organ, a coupler may connect the division's keyboard, actually moving its keys. Even an electric or other indirect action organ may have mechanical couplers, which produce the same effect.

Larger organs sport octave couplers and suboctave couplers, which shift the connection by an octave up or down, respectively. It is rare for the ranks of a division to have been extended to accommodate such couplers.

Case or chamber

In all but the smallest pipe organs, the pipes are housed either in a free-standing organ case or in a dedicated room called an organ chamber. In either case, the pipes are separated from the listeners by a facade or grill that often contains decorative pipes known as a prestand.

In some organs these prestand pipes are genuine, sounding pipes, most often but by no means always an open flue rank from the pedal division. The reason for this choice is that these pipes are large in size and small in number, and have a traditional appearance. In other organs, the prestand pipes are purely decorative.

Even with a non-standing prestand, the facade is considered a valuable part of any pipe organ, much as the scroll of a violin is considered part of that instrument.

Organ music

See the main article organ repertoire and the article on early organ tablature.

There is a large repertoire of religious music for the pipe organ. Many composers, including the Baroque composer Johann Sebastian Bach, have written for the pipe organ. Music written for the pipe organ is common from the Renaissance to the present day; North Germany is particularly notable for having produced many composers for the instrument.

In popular music:

Notable organ builders

Some notable pipe organs

Missing image
The organ of Bristol Cathedral, Bristol, England. Many of the pipes date back to 1685 although the organ has been rebuilt many times since then.

The world's oldest playable pipe organ is located in the Basilica of Val貥 in Sion, Switzerland. Built around 1390, it still contains many of its original pipes.

The largest pipe organ ever built, containing more than 32,000 pipes, is the Main Auditorium Organ in Atlantic City Convention Hall, built by the Midmer-Losh Organ Company between 1929 and 1932.

The largest functioning pipe organ, with over 28,000 pipes, is the Grand Court Organ at Wanamaker's department store (now Lord and Taylor) in Philadelphia. It is also the second largest organ yet built.

The largest tracker action pipe organ in the world is the Sydney Opera House Grand Organ, with 10,154 pipes.


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