Pipe organ

The baroque organ in Roskilde Cathedral, Copenhagen

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, prompting Wolfgang Amadeus Mozart to name it the "king of instruments".

The basic components of a pipe organ are pipes 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 immediately. Modern organs usually include more than one keyboard playable by the hands (called a manual) and a large keyboard playable by the feet (a pedalboard). The most common configuration is two manuals with a pedalboard. Large organs have four or five manuals, although some of the very largest organs have even more than this.

The organ has been described as one of the oldest musical instruments, as its origins can be traced back to the third century BC in ancient Greece. The organ developed from the water organ into an instrument in which the wind was supplied by bellows. Early portable organs were used to accompany both sacred and secular music. During the Renaissance period, the organ developed from a simple instrument toward one where the player had full control over the sound produced; by the Baroque era at the end of the seventeenth century, the organ had developed into much the same instrument as we see today.

Pipe organs are commonly found in Christian churches and some Jewish synagogues, as well as in town halls and arts centres where they are intended for the performance of classical music, especially for transcriptions of orchestral music. The organ boasts a substantial repertoire of both sacred and secular music spanning a period of over 400 years.

Pipes

Main article: Organ pipe

A set of flue pipes.

Organ pipes are the sound-producing elements of the pipe organ. These pipes are made from either wood or metal and produce sound when pressurized air (referred to as wind) is allowed to pass through. The pipes are arranged into ranks—complete sets of pipes of similar timbre tuned to a musical scale. Each rank is activated by the organist through the stop mechanism. These ranks are mounted vertically onto a windchest that supplies wind to the pipes; several ranks of pipes can be supplied by a single windchest. There are two main types of organ pipes: flue pipes, which are actuated by a fipple similar to a recorder, and reed pipes, which contain a beating reed in the manner of a clarinet.

It is the action of the organ that admits the wind into each pipe when a key is depressed by the organist. There are many varieties of action; however, they fall into two principal groups: mechanical action and electro-pneumatic action. Mechanical key action (also called tracker action) refers to a direct connection between the keys and the windchests achieved through a series of wooden or metal rods called trackers. When the organist depresses a key, the trackers move, allowing wind to enter individual pipes. In organs with a mechanical stop action, draw knobs (also called stop knobs), visible on either side of the console, are physically connected to each rank of pipes on the windchests. When the organist "draws" a stop knob towards himself, the stop action conveys the motion of the stop knob to the windchest, actuating the mechanism at the windchest that allows wind to flow into the selected rank of pipes.

Electro-pneumatic actions control the mechanisms at the windchest through the use of pneumatic air pressure, controlled by an electric current, to open and close the valves within the windchest, allowing the pipes to speak. Because physical contact between the keys and stops and the windchest is not required, this system allows the organ console to be separate from the rest of the instrument (albeit connected by electrical wiring). Some organs with electro-pneumatic action use rocker-tab switches instead of draw knobs; rocker-tabs use electrical contacts to activate the pneumatic system. Because the key action and the stop action are separate from each other, it is possible (and quite common) for an organ to feature a mechanical key action and an electric stop action.

Wind system

A view from behind the case of the organ at St. Raphael's Cathedral in Dubuque, Iowa shows some of the pipes, the interior of the case, and part of the wind system.

The pressure of wind supplied to a pipe organ is measured, by a manometer, in the USA and the UK in inches of water (in other countries this is often in the metric millimetres of water). Although strictly unscientific, pipe organs are said to be "on x inches of wind".

In order for the pipes of an organ to sound, the wind that will supply the pipes must be produced through some method. The original form of wind generation was mechanical. When signalled by the organist (often by a small bell), a calcant (the bellows operator) pumped the bellows of the organ, supplying them with air. Playing the organ before electricity required at least one person to operate the bellows. Compensating calcants was expensive; thus, organists would usually practice on smaller instruments such as the clavichord or harpsichord. A few organs that can be mechanically pumped still exist, and modern instruments have been built with this capability.

After the use of electricity became widespread, electric motors called blowers were used to fill the bellows with air. Suddenly, it became possible for organists to practice regularly on the organ. The majority of all organs, new and historic, now make use of this modern technology. It is possible that, before electricity, some organs were fitted with motors (often water turbines) which manipulated the bellows through the use of a crankshaft.

Once the wind has been produced, it is stored in one or more reservoirs, which keep the wind supply at a constant pressure. This pressure differs depending on the design of the organ and the division the wind supplies. An Italian or Iberian organ from the Renaissance era may feature a wind pressure of only 2.2 inches (56 mm), while an orchestral organ from the early twentieth century may have wind pressures as high as 25 inches in some divisions.

The wind flows from the bellows through one or more large tubes known as wind trunks to the separate divisions of the organ. There, the wind is fed into the windchest, on which the pipes are seated. Then, through the key action, the wind flows into the pipes, causing them to sound.

Stops

Main article: Organ stop

Each rank of pipes in an organ is called a stop. Because each pipe can produce only one pitch, there is usually one pipe per note for every stop. Some stops, known as mixtures, allow several ranks to be controlled by one stop, eliminating the need for several individual stop controls. The name of a stop refers to the sound it produces, although stop names are not always consistent. Indeed, many stops that produce 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 a French Romantic organ will come from the French 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 stop that sounds at unison pitch (the same pitch as a piano) is referred to as being at 8′ (pronounced "eight-foot") pitch. This is because the length of the longest (and lowest-sounding) pipe in that stop is eight feet. A stop that sounds an octave higher is at 4′ pitch, one that sounds two octaves higher is at 2′ pitch; a stop that sounds an octave lower than unison pitch is at 16′ pitch, and one that sounds two octaves lower is at 32′ pitch.

Stops of the Baroque organ built by Gabler in Weingarten, Germany.

A traditional stop label on a draw knob or rocker-tab includes two parts:

• the name of the stop (Diapason, Rohrflöte, Cornet, Trompette, etc.)
• the pitch level (8′, 4′, etc.), or the number of ranks controlled by the stop (III, IV–VI, etc.)

Thus, a stop labelled "8′ Chimney flute" is a single-rank flute stop sounding at 8′ pitch. A stop labelled "Mixture V" is a five-rank mixture.

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 divisions. 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, c′) is pressed, two pipes of the same rank will sound: the key played, and the octave above.

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. An organ that relies heavily on extension is called an extension organ.

Some organs feature various percussion stops and effects that have no pipes at all, such as the "Zimbelstern" (a revolving, star-shaped wheel of bells), the "Nightingale" (a stop that blows wind through a whistle submerged in a small pool of water, creating the sound of a bird warbling), and the "éffet d'orage" (literally, "effect of thunder," common on French organs of the nineteenth century), involving many of the large bass pipes of the organ sounding together. Other orchestral percussion-type stops include the "Drum", "Chimes", "Celesta", and "Harp".

Organ stops are the origin of the phrase "to pull out all the stops", meaning to make every effort or "to give it all you've got".

Console

Main article: Organ console

The five-manual console for the organ at the United States Naval Academy Chapel. The pedalboard is also visible.

All the controls available to the organist are collected together in an area called the console. This includes the manuals and pedals, the expression pedals, the stop controls and associated registration aids, and the couplers.

Keyboards

The console features 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, meaning "hand"): for example, 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 stops controlled by a particular manual is called a division. 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.

Enclosure and expression pedals

Main article: Expression pedal

Enclosure is the term for a system that allows for the control of volume (crescendo and diminuendo) without requiring the addition or subtraction of stops. All the pipes of an enclosed division are surrounded by a box-like structure called the "swell box." At least one side of the box, usually that facing the console or the listener, will be constructed from horizontal palettes (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 when it is "closed."

In many organs, at least one division will be enclosed. In a two-manual organ with Great and Swell divisions, the Swell division will be enclosed (which is why the division is named Swell). In larger organs, often part or all of the Choir and Solo divisions will be enclosed as well.

The most common form of controlling the level of sound released from the enclosed box is by the use of a balanced expression pedal. This is usually placed above the centre of the pedalboard, rotating away from the organist from a near horizontal ("open") to a near vertical position ("shut").

In addition to an expression pedal, an organ may have a similar-looking crescendo pedal, which would be found to the right of any expression pedals. Applying the crescendo pedal incrementally activates all the stops in the organ, starting with the softest stops and ending with the loudest.

Combination action

Different combinations of stops produce different sounds. A specific combination of stops is called a registration. On modern organs, a large change of registration involving many stops can be effected instantaneously with the aid of a combination action, usually featuring pistons, buttons that can be pressed by the organist to change registrations. They are generally found in the space ("keyslip") between the manuals ("thumb pistons") or above the pedalboard ("toe studs/pistons"). Most large organs have both preset and programmable pistons, with some of the couplers repeated for convenience as pistons and toe studs. These complicated registration aids, such as thumb and toe pistons (which can draw several stops in one action), require an electro-pneumatic action, although a rudimentary system is available with a mechanical action.

Couplers

A coupler allows the pipes of one division to be played by another keyboard. For example, a coupler labelled "Swell to Great" allows the stops drawn in the Swell division to be played by the Great manual. By using couplers, all of the resources of an organ can be played simultaneously from one manual or pedalboard. On a mechanical-action organ, a coupler may physically connect one manual to the other, so that the keys on all the coupled manuals are depressed, even though the organist is only in contact with one of them.

The Swell to Great coupler described above is a unison coupler, one which causes the pipes of the Swell division to sound at the same pitch as the keys played on the Great manual. Some organs also feature octave couplers, which add the pipes an octave above ("super octave" or sometimes just "octave") or below ("sub octave") to that which is being played by the fingers. Octave couplers may operate on one division only (for example, the "Swell octave," which adds the octave above what is being played on the Swell to itself), or they may act as a coupler (for example, the "Swell octave to Great," which adds to the Great the ranks of the Swell division an octave above what is being played on the Great manual). Octave couplers may also be used in conjunction with the standard unison coupler.

In addition, some organs feature "unison off" couplers, which prevent the stops pulled in a particular division from sounding at their normal pitch. While this feature is seemingly counter-intuitive, unison off couplers can be used in combination with octave couplers to create innovative aural effects. In addition, they can be used to effectively rearrange the order of the manuals, in order to make specific literature easier to play.

Casing

The free-standing organ in St. John's Cathedral, 's-Hertogenbosch boasts one of the most striking organ façades in the Netherlands.

File:Kaltenbrunnerorgantaiwan.jpg

The pipe organ at the Aletheia University in Matou/Taiwan, an example of a modern case design.

The organ of Bristol Cathedral, Bristol, England. Some of the pipes date from 1685.

The elements of most organs are housed in a free-standing organ case or a dedicated room called an organ chamber. The free-standing case is considered by most organists and organ builders to be acoustically superior to the chamber because it is said to focus the sound of the organ and project it into the room. The great organ builders of the Renaissance and Baroque periods built organs exclusively in free-standing cases, often with extensive decorative touches such as carved pipe shades, edge mouldings, and even statues.

During the latter portion of the nineteenth century, the shift to chambers began, followed shortly by the shift to electro-pneumatic action. By the mid-twentieth century, some organists (most notably E. Power Biggs) were pleading for a return to the old construction methods (i.e., mechanical action organs in freestanding cases).

In either type of construction, the pipes are separated from the listeners by a grille known as a façade, which often contains decorative pipes. Some organs do not have any discernible pipe façade, or the pipes may be hidden behind a screen. In many organs with façade pipes, especially those based on historical styles from the time before the twentieth century, the façade pipes are connected to the keys and are fully playable. They usually form part of the primary Principal stop from the Pedal or Great division. In other organs, the façade pipes are purely decorative and non-speaking. Whether or not the façade pipes speak, the façade is considered an important part of an organ (much as the scroll of a violin is considered a part of that instrument).

History and development

Reconstruction of Hero of Alexandria's wind-powered organ (first century AD).

File:StCeciliaPortativ.jpg

A painting of Saint Cecilia playing a portatif with a set of hand-pumped bellows (Meister des Bartholomäus-Altars, 1501).

The organ is one of the oldest instruments still used in European classical music. Its earliest predecessors date to the third 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 the Greek engineer Ctesibius of Alexandria, who created a hydraulic (water-powered) instrument called the hydraulis in the third century BC. The hydraulis was common in the Roman Empire, where its incredibly 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; a working, reconstructed instrument is owned by Aquincum Museum in Budapest. The exact mechanism of wind production is still debated, but the tone of the original pipes can be studied. Almost nothing is known of the actual music it played. The pumps and water regulators of the hydraulis were replaced by bellows in the second century AD.

File:CDolciCecilia1671.jpg

Carlo Dolci's painting of Saint Cecilia at a portatif organ, 1671.

Organs were also known to exist in the Byzantine Empire as well as in Islamic Spain. In medieval times, portable organs (the portative organ or Portatif and the positive organ) were invented. Towards the middle of the thirteenth century, the portatives represented in the miniatures of illuminated manuscripts first show signs of a real keyboard with balanced keys, as in the thirteenth-century Spanish manuscript known as the Cantigas de Santa Maria. Because of their portability, the portative was used for the accompaniment of both sacred and secular music in a variety of settings.

As pipe organs 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 or on the "Blockwerk", the entire tonal resources of the organ. In some cases, this meant a very large number of ranks ranging from 16′ pitch all the way through 1′ pitch and higher.

Eventually, controls were designed 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

File:DirkvdM organ oude kerk.jpg

The Baroque organ of the Oude Kerk in Amsterdam, the Netherlands.

During the Renaissance and Baroque eras, the organ became an instrument capable of creating numerous tonal colours, 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 labelled the Werkprinzip by twentieth-century musicologists. In France, the French Classical organ came into fashion, a style of building articulated most completely by Dom Bédos de Celles in his treatise, L'art du facteur d'orgues (The Art of Organ Building).

Romantic era

The English Romantic organ at the Parish Church of Saint Mary the Virgin in Ewell, Surrey.

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 twentieth 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.

Modern development

A major revolution in pipe organ design took place in the late nineteenth century when the development of pneumatic, electric, and electro-pneumatic key actions made it technically feasible to locate the console independently of the pipes. In the middle of the twentieth century, organ builders began to build historically-inspired instruments. At this time, they returned to mechanical key action in order to regain the subtle, nuanced control it gives the performer. During the twentieth century, electrically-controlled stop actions allowed for the development of sophisticated combination actions.

The 2006 Rembrandt Digital organ, an example of a large pipeless organ that could be used in a church.

In the mid-twentieth century, pipeless electronic organs were developed. Many true pipe organs were replaced due to the cheaper initial cost and smaller size of pipeless organs. Although the entire sound of a pipe organ cannot yet be completely recreated, pipeless instruments are still a viable alternative to a true pipe organ for many churches and other organizations due to the lower costs involved, the lack of maintenance required, and the smaller amount of space necessary. The use of digital technology has advanced to such a level that there is now very little difference in sound timbre between piped and pipeless instruments, though organists and organ builders generally agree that there is no substitute for a true pipe organ. It is increasingly common for builders of new pipe organs to use individual digital stops for the very lowest pedal ranks of their organs, owing to the economy of space and resulting lower cost.

Developments in the computer industry began to be incorporated into pipe organs using the techniques developed for pipeless organs, incorporating them as "digital" components into real pipe organs. This allowed for simpler actions and more reliable combination action systems. Another modern development is the MIDI recording system, which can record and replay an organist's performance, and can even download files of these recordings onto a computer.

Repertoire

Main articles: Organ repertoire, Organ tablature, List of organ pieces, and List of organ composers

Overview

The development of organ repertoire has progressed hand in hand with the development of the organ itself, 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 (the United Kingdom, France, Germany, the Netherlands, and the United States). Thus the repertoire from countries such as Spain, Portugal, and Italy is less commonly heard, because fewer pieces have been written by the composers of these countries, and because the tonal styles of the organs in these countries are quite different. Likewise, there is little Russian or Greek organ music because those nations' Orthodox churches do not use the organ in worship.

Organ music is generally written on three staves (two for the manuals and one for the pedals), but up to five staves have been utilized in more complicated music. Some organ music, especially music from before the nineteenth century, is written on only two staves, with the pedal notes written on the bottom staff as a divisi part.

There is a large repertoire of sacred music for the pipe organ. This reflects the fact that organs are commonly found in Christian churches, as well as in some Reform and Conservative synagogues. Organs in these venues 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 usually played before and after the service. These pieces are generally called voluntaries.

Because pipe organs have been built in non-sacred venues such as in town halls and arts centres, much secular music has been written for the pipe organ. Organs in these buildings are 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 theatres. Large pipe organs with automatic mechanical player mechanisms were often found in the mansions of the very wealthy in early twentieth-century America. Today, small pipe organs can be found in the homes of organists for use as practice instruments.

Solo music

A portrait of Johann Sebastian Bach (Elias Gottlob Hausmann, c.1748).

Although most countries whose music falls into the Western tradition have contributed works to the organ's repertoire, France and Germany are particularly notable for having produced many exceptional composers for the instrument. There is also extensive repertoire from the Netherlands, England, and the United States. The majority of the organ repertoire 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. The Baroque period is well represented by other German composers such as Dieterich Buxtehude, Johann Jakob Froberger, and Johann Pachelbel. French organ music developed at this time under the so-called "French Classical" period through the music of François Couperin and Nicolas de Grigny.

In the Romantic period, many French organist-composers such as César Franck, Charles-Marie Widor, Louis Vierne, and Charles Tournemire pushed the genre of organ music into the symphonic realm as did German composers like Felix Mendelssohn, Josef Rheinberger, and Max Reger.

A great amount of organ literature was also written in the twentieth century. Olivier Messiaen, one of the most highly regarded organists of twentieth-century France, is considered one of the most important composers for the organ since Bach. Messiaen re-defined many of the traditional notions of organ registration and technique in order to realize his musical concepts. In addition to Messiaen, composers such as Marcel Dupré, Jean Langlais, Maurice Duruflé, Herbert Howells, Hugo Distler, and Petr Eben have made significant contributions to the organ literature.

Orchestral music

The organ has been integrated into many orchestral works, 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 concerto were written by George Frideric Handel. Some of the composers who used the organ prominently in their orchestral music are Gustav Holst, Richard Strauss, Ottorino Respighi, Gustav Mahler, Anton Bruckner, and Ralph Vaughan Williams.

Works cited

• Thistlethwaite, Nicholas and Webber, Geoffrey, editors. The Cambridge Companion to the Organ. Cambridge: Cambridge University Press, 1998. ISBN 0-521-57584-2

Further reading

• Sumner, William Leslie. "The Organ: Its Evolution, Principles of Construction and Use." ISBN 0-7812-0572-7
• Williams, Peter. "The European Organ, 1458–1850." Nashua, New Hampshire: the Organ Literature Foundation, 1966.

External links

• Pipedreams Listen to hundreds of hours of pipe organ music online, view organ pictures and specifications
• Sacred Classics Online program of pipe organ and choral music
• The Pipe Organ
• 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
• Bach's Organ Tuning
• Flue Pipe Acoustics

Databases

• Organ Historical Society Pipe Organ Database
• The Top 20 - The World's Largest Pipe Organs
• United States Pipe Organ Directory
• National Pipe Organ Register (NPOR) - Database and specification of every pipe organ in the United Kingdom
• The world's largest organs with photos and stoplists
• A searchable database of North American Organs