# Organ pipe

Organ pipes in the Concert Church in Neubrandenburg

Organ pipes are the sound-producing parts of an organ . Each pipe can basically only produce a certain tone of a certain timbre and volume, so that a large number of different pipes are present in one organ (several thousand in larger organs). In order to enable the different pitches, timbres and volumes , pipes of different sizes and designs are used. Whistles are grouped into registers that can be individually switched on and off in order to be able to change the sound of an organ while it is playing. According to the principle of sound generation, there are two basic types of pipes: Labial pipes (lip pipes, sound generated by breaking airflow) and lingual pipes (reed pipes, sound generated by a vibrating metal tongue).

## materials

Organ pipes of a swell

Organ pipes are made almost exclusively of wood or metal . The main metal used is an alloy of tin and lead with different mass ratios, which is known as organ metal . In addition, copper (one of the oldest materials used in organ building) or, from the middle of the 19th century to around the middle of the 20th century, zinc is also used, especially when replacing pipes melted down for war purposes.

Wooden pipes can be made of different types of wood, usually oak, coniferous or fruit woods, occasionally also exotic woods. Wooden pipes are usually filled with glue on the inside, because small leaks considerably hinder the generation of sound. Organ pipes were also made from bamboo , porcelain , plastics and, in earlier times, even ivory. In contrast to the labial pipes, where the choice of material (possibly with the exception of the core) affects the whole pipe, reed pipes are always made of different materials. Different types of wood, leather and different metals can be used ( see below for a more detailed description ).

## Labial pipes (lip pipes)

The sound generation of the labial pipes (lip pipes) is based on the fact that a band of air is blown through a narrow gap against an edge, the labium (see below, section Sound generation). This corresponds to the principle of the recorder and other beaked flutes .

Audio sample: Rohrflöte 8 ′ ? / i (853 kB)

### construction

#### Overview

 Metal labial pipe : (1) pipe body (2) upper labium (3) core (4) side beard (5) cut (6) lower labium (7) core fissure (8) pipe foot (9) foot hole Labial pipe made of wood: (1) pipe body (2) upper labium (3) core (4) side beard (5) cut (6) suggestion (corresponds to the lower labium of a metal pipe) (7) core column (8) pipe foot

Although the sound generation is the same for all labial pipes, they differ somewhat depending on the material they are made of. Labial pipes made of metal usually have a circular pipe body, while wooden pipes mostly have a rectangular pipe body for practical reasons, but occasionally there are also turned round wooden pipes. The names of the components are slightly different.

#### Pipes of metal

Labial pipes with gold-plated labia

From a functional point of view, metal labial pipes consist of two parts, the tapered pipe foot, with which the pipe stands on the pipe stem or on the front cornice, and the pipe body, which can have different shapes and is responsible for producing the sound. Both the foot and the pipe body are almost completely closed in the transition area with a soldered-in horizontal plate, the core. A segment of the otherwise circular core is cut off on one side and the foot is not soldered to the core at this point, but pressed so far towards the straight edge of the core that a narrow, parallel gap forms, the so-called core gap. The indented point on the foot is called the lower labium. The front edge of the core is beveled upwards; this bevel is called the core bevel.

The pipe body is soldered on top of the core. A mostly rectangular opening, called a cold cut or mouth hole, is cut out of the pipe body above the core fissure. The upper edge of the cut forms the upper labium. In the case of small pipes, the labium is pressed into the body of the pipe (pressed-in labium), while in larger pipes it has to be soldered (attached labium). For optical reasons, larger prospect pipes, especially if they have a round labium and not a pointed labium, also have the lower labium soldered in.

As a rule, a pipe only consists of these parts. Certain registers still need beards as an intonation aid. These are small metal plates, the length of which corresponds approximately to the height of the cut and which protrude to the front and are soldered to the side of the labium opening. In some cases there is also a beard horizontally in front of the lower labium. If this consists of one part together with the side whiskers, the box beard is called, if this is vertical it is referred to as a mustache, a cylindrical piece of wood or metal between the side whiskers is called a roll beard (rarely used today). Capped organ pipes have a cover as a further part, which is attached with a sealing strip made of felt or fabric (with very old organs also firmly soldered). In rare cases, open pipes also have a tuning ring that is roughly comparable but open at the top.

#### Wooden pipes

Wooden labial pipes do not have a lower labium in the actual sense. The proposal serves here to limit the core gap . The upper labium is filed, milled or chiselled into the pipe body. Depending on whether it is inside or outside, it is called a innenlabiierten or außenlabiierten pipe. The latter design is the usual one. Three of the four side parts of a wooden pipe are continuous, so to a certain extent result in what is the foot and pipe body of a metal pipe. In the lower part of the suggestion is the core, in which the pipe base is embedded. This usually consists of a wooden pipe. In order to influence the wind (amount) there is often a possibility for wind regulation built into the foot, e.g. B. in the form of a wide screw.

Often, closed registers are made of wood, they then have a lid with a handle sealed with felt or leather. Occasionally side beards are put on in the form of small wooden strips, but as a rule the side walls (of the mostly outside labi pipes) already form a kind of side beards due to their protrusion. Often, as a beard in the proposal, narrow metal plates are let into a slot parallel to the core gap, the protruding part then serves as an intonation aid. As a rule, open wooden pipes also have a curved sheet metal at the top, with which the size of the mouth of the pipe is regulated. This makes it possible to tune the pipe.

### Pipe length

Foot indication and (real) pitch of open labial pipes (1 ′ = 1 foot = approx. 30 cm)
Schematic sketch, especially the large pipes are in reality considerably thinner

The length of the pipe directly determines the pitch of the labial pipes. The length ranges from a few centimeters to a few meters. A distinction is made between open pipes and the Gedackten , which are closed at the top with a lid or bung. Bounded pipes sound an octave lower than open pipes of the same length. Open conical pipes are deeper the more they taper towards the top. The length of the largest pipe of a register is determined by its foot position and also indicated in this. In the normal pitch, the equivalent register, the lowest pipe of such a register is usually about eight feet, i.e. about 2.4 meters (plus the pipe foot) long. Smaller organs only have stops in 8 'position or higher, larger organs often have stops in 16' position, very large instruments even in 32 'position and in individual cases even 64' position. However, their frequency is partly below the limit of the human hearing range ( infrasound ) and can only be perceived as a shock and feeling of pressure on the ears. The subcontra-C is the lowest tone of a 32 'register and produces, for example, a tone at 16.35  Hz . Very small pipes only sound a few millimeters long. In these pipes, however, the pipe foot, which does not contribute to the sound generation, is usually around 15 centimeters long. The tones of these smallest pipes almost reach the upper limit of human hearing.

The length l P of the pipe body of an open cylindrical labial pipe can be calculated from the frequency f and the speed of sound c S (= 343 m / s for 20 ° C in air) as follows (λ is the wavelength):

${\ displaystyle l _ {\ mathrm {P}} = {\ frac {\ lambda} {2}} - k = {\ frac {1} {2}} \ cdot {\ frac {c _ {\ mathrm {S}} } {f}} - k \,}$

Here k is the muzzle correction (also called practical shortening ), which depends on the pipe diameter d . It is also called the final correction of the resonator length . It is necessary because the belly of the standing wave is not exactly at the end of the pipe, but somewhat outside. The French organ builder Aristide Cavaillé-Coll has found the following formula for them, which provides a rough guide:

${\ displaystyle k = {\ tfrac {5} {3}} d}$

Although the muzzle correction also occurs in principle on the pipe mouth, in practice it plays a rather insignificant role with closed pipes. The length l G of a closed cylindrical pipe is:

${\ displaystyle l _ {\ mathrm {G}} = {\ frac {\ lambda} {4}} = {\ frac {1} {4}} \ cdot {\ frac {c _ {\ mathrm {S}}} { f}} \,}$

An excess length may be necessary for acoustic reasons if you want to overblow the labial pipe ; the lowest then audible tone of the pipe is then its first overtone. Overblowing is facilitated by a small hole in the pipe wall about halfway up, sometimes also by a relatively narrow design and above all by a relatively high amount of wind. Overblowing into further overtones is also possible under very specific possibilities. As a rule, overblowing pipes are cylindrical and open and in this simplest case are then twice as long as a non-overblowing pipe of the same pitch. Pounded pipes generally lack every second partial, so they overblow into the second overtone and are then three times as long.

### Scale length

(From Latin mensura 'measure')

The length of a pipe essentially determines the pitch. The cross-section as well as the labia width and height of the cut (and the amount of wind supplied or the wind pressure) shape the timbre. All these dimensions of a pipe are summarized under the term scale length . In the narrower sense or in general usage, the term scale length initially only refers to the width scale, i.e. the ratio of length and width or diameter.

The most important lengths for labial pipes are:

• the length gauge : the length of the pipe body (it determines the pitch),
• the width gauge : the ratio of the diameter to the length of the pipe,
• the width of the labia : the width of the labium in relation to the circumference of the pipe,
• the height of the cut : the distance between the upper and lower labia in relation to the width of the labia.

Further parameters that influence the sound and the response of a pipe are, for example, the core gap width and foothole size.

For non-cylindrical pipe shapes (reed flute, gemshorn, capping pipe, pointed flute, etc.), additional dimensions are required accordingly. The width scale is the most important scale length in organ building, from which the division into “narrow”, “medium” or “wide” metered registers results. The slicing dimensions are often derived from the circumference of the pipe body.

Certain dimensions (actually predetermined during manufacture by the selected scale length) can still be changed in part for the intonation of the pipes. Voicer Rainer Janke, for example, writes of 55 parameters, and that the height of the cut and the wind pressure have significantly more influence on the sound of a labial pipe than the diameter.

1927 decided German Orgelrat with Normmensur first time, a standard measure of the scale. It goes back to the organ builder Dom Bédos (1709–1779) and the organ building theorist Johann Gottlob Töpfer (1791–1870). According to Dom Bédos, the deepest pipe of the so-called standard principle in the 8 'position has an inner diameter of 155.55 mm. A pipe that sounds an octave higher is only half the sounding length, but its diameter is not halved as well, but is calculated using the formula for the standard gauge:

${\ displaystyle 1: {\ sqrt [{4}] {8}} \ approx 1: 1 {,} 682 \,}$

This means that only the pipe that sounds an octave plus a major third higher gets half the diameter, the high pipes of a register therefore become wider and wider, the low ones, however, always narrower. If the diameter doubles or halves in octave intervals ( rigid diameter gauge ), the pipes of the same register would sound very different in their course. When using the Potter scale, these acoustic differences are compensated as well as possible.

At times, the standard gauging was used directly for scaling principal registers and was only used slightly changed ( shifted ) for other registers . Today it is mainly used as a benchmark for classifying and describing the scale lengths, but it is rarely used in practice. Scale lengths and scale diagrams are created by calculating the deviation from the standard scale in semitones (HT). Positive numbers mean a wider and negative numbers mean a narrower scale. Has z. For example, a pipe that emits the tone c 2 has a width gauge of −4 HT, its diameter corresponds to that of the four semitones higher and therefore narrower pipe e 2 of the standard gauge (and would therefore be exactly half the diameter of the pipe for the tone c 1 ). Similarly, the following rule of thumb can be used for the labia or slice width and height: slice height = 14 * slice width = 14 * circumference = diameter of the normal dimension * (number of circles) and deviations from this can also be stated in semitones. ${\ displaystyle \ pi}$

Examples of scale courses (1874)

As can be seen from the figure, the width measurement can vary within a register. One then speaks of a variable (as opposed to constant or rigid) progressive measurement . Variable lengths are the rule. They can be used to emphasize or weaken the different pitches of a register.

### Sound generation

The air flows through the base of the pipe and emerges from the core fissure as a band of air directed towards the upper labium. This is where the air flow is deflected and begins to swing alternately outwards and inwards (for details see woodwind instrument ). Various feedback effects also stimulate the air in the pipe body to vibrate. These vibrations can be perceived as a sound after they have stabilized in the frequency given by the pipe length . The transient processes up to the formation of the stable pipe sound are called speech . This is made up of blowing noises and briefly occurring high-frequency precursor or cutting tones that have a significant impact on the sound of the pipe, such as the so-called spitting when the registers are closed . The duration and character of the speech initially depend on the type of pipe, wind pressure and height of the cut. The speech ends when the actual or stationary sound is reached.

With a sounding open pipe there is a vibration belly at the upper and lower end, i.e. at the mouth and labium. In the middle of the pipe there is a vibration node, at least in relation to the fundamental. If the pipe length is halved and closed in the middle, depending on the number and location of the wave bellies and nodes, not all natural overtones fit into a closed pipe. Every second overtone (i.e. every even-numbered partial or every odd-numbered overtone) cannot be generated. This creates the warm, round sound of the closed registers. The very unique sound of overblowing registers is explained in a similar way. Since the actual fundamental tone, the first tone of the natural partial series, is missing, all other overtones move up one place in comparison to the “effective sounding fundamental tone”.

Again, it is similar with the different designs and sizes. While each tone (in contrast to noise) is defined per se by the existence of the natural overtone series, the different, characteristic sound of a tone results depending on how strongly each of the existing partials is pronounced. Exactly this is created by the variety of shapes of organ pipes.

Until some time ago it was suspected and also proven by older studies that the pipe material, possibly even the processing of a similar material, had an effect on the sound. Similar effects on the sound were also attributed to those pipes of particularly historical organs, the metal of which is thinned towards the mouth. These influences could only be proven to a limited extent in recent studies: The oscillation of the air column causes oscillations in the pipe wall. These wall vibrations actually turn out very differently depending on the wall material. The effect on the audible airborne sound is small, however, so that the influence of the material can usually be compensated for by the intonation (see below). However, the choice of material can determine the thickness of the pipe wall and thus restrict the possibilities of intonation somewhat. The age of a pipe also has no influence on its sound, but rather the different intonation methods of earlier times. However, damage to the pipes definitely has an impact on the intonation, in addition to deformations, the tin plague should be mentioned.

### Types

The shape of the pipe significantly determines its timbre .

#### Classification

The most important labial registers can be classified according to their type as follows:

• Cylindrical open pipes of medium length form a tone that corresponds to the generally known organ tone with a full, tart sound. Commonly used names here are principal , prefix and octave . The sound crowns , collectively called mixtures, are also part of it. These registers form the so-called principal choir .
• Cylindrical open pipes with a wide length have a full, smooth sound. One speaks of this pipe family as a wide choir . It has the lowest overtones and is therefore suitable as a stable basis for the sound of an organ. Since pipes with wide bores merge well with each other, most of the aliquot registers (fifth, third, seventh, ninth; mixed voices such as cornet) are also wide bored. Register names include flute , hollow flute , wood flute , Nachthorn .
• Cylindrical open pipes with a narrow scale are sharp with a weaker sound that is very rich in overtones. Since the sound is reminiscent of string instruments, the registers have been given appropriate names: viola , violin , gamba , Salizional (willow pipe ) is also common . This usually includes the floating voices such as Vox coelestis and Unda maris . This family is called the string family or eng choir .
• Pipes that taper conically towards the top amplify individual overtones. This results in a slightly brighter sound. Here you can find registers such as the pointed flute , recorder and gemshorn .
• Inverted conical, i.e. funnel-shaped pipes are a bit tart, such as the Dolkan (also Dulcan ).
• Overblowing pipes are characterized by a pronounced, yet soft response and a full sound. They are used almost exclusively on cylindrical registers, such as the flute and flûte harmonique .
• Cylindrical closed pipes ( Gedackte ) are available in different widths. They are quieter and have fewer overtones. The middle scale length (for example Gedackt , Bordun , Subbass , Untersatz ) often form the foundation for the organ sound and, especially in smaller partial works, are one or two octaves lower than the lowest principal register. This is where the space-saving property of the Gedackten comes into play. Gedackte wider scale (Gedackflöte) form the basis for solo registrations with aliquot registers. With the exception of the quintadena, the narrow measure lengths are rare.
• Half-closed pipes have a hole in the lid or a tube that leads inwards or outwards.

#### Systematics

Different designs of organ pipes, all of which produce a tone of the same pitch:
Labial pipes made of metal: (1) principal, (2) open flute, (3) viol, (4) pointed flute, (5) funnel flute, (6) Gedackt, (7 ) Gedackt flute, (8) quintade, (9) reed flute, (10) pointed flute.
Labial pipes made of wood: (11) Principal, (12) Open flute, (13) Gedackt, (14) Gedackt flute.
Lingual pipes: (15) trumpet, (16) krummhorn, (17) dulzian, (18) wooden shelf, (19) trumpet shelf, (20) funnel shelf, (21) double cone shelf.
Schematic sketch, all pipes are actually a bit thinner.

Systematics of shapes (and diameters) of the pipe body and registers

 Labial pipes dacked half-open: reed flute hollow flute open cylindrical: Gedackt Subbass Bordun Quintade conical: pointed cylindrical: conical: Gemshorn pointed flute Nasat recorder narrow (strings): Basic parts : (Viola da) Gamba Salizional Cello Violon Fugara registers with multiple occupations : Harmonia aetheria medium (principals): basic parts: principal octave praestant aliquot parts: fifth third multiple stops: Rauschpfeife Sesquialtera Terzian Mixtur Scharff far (flutes): Basic Votes: Flute Forest Flute Nachthorn coupling flute (with tapered tower) Aliquotstimmen: Nazard (Nasat) third multi-occupied Register: Cornet Sesquialtera

### intonation

#### definition

The term intonation describes the design of the sound of the organ pipes. The area of ​​the labium is processed with special tools in order to change the tone color and volume of the pipe and to obtain a stable tone that it does not have immediately after production. In addition, all the pipes of a register must be balanced and tuned in terms of sound character and volume, both in and of themselves. The voicer incorporates the style of the organ and the room acoustics into his work. In addition to the intonation, the sound of an organ is essentially determined by the scale lengths.

The alloy (for pipes made of tin and lead), the processing and the age of a pipe, on the other hand, have almost no effect on the sound, since it is not the material of the pipe that vibrates but the air.

#### Intonation means

In order to influence the sound of a pipe, there are, in addition to the various designs, an abundance of possibilities that can be described as intonation means. These include: expressions, vocal slots, beards, cut heights, core gap width and their nature, core bevel and back bevel, shape and position of the upper and lower labium, shape and number of core stitches and the size of the foothole. The means of intonation have been further developed over the centuries in the course of organ building history and, in their diversity and differentiated use, reached a high point during the Romantic era.

 Foothole expand louder, sharper, more forced, faster, mood higher, sharper response (if the pipe is cut very high: less spitting), possibly less hissing or bubbles, more scratching narrow quieter, more basic, sweeter, slower, lower mood, softer response (longer spitting with high cuts), possibly more hissing or bubbles, less scratching Upper labium press in slower, sharper, more principled, speech a little more blunt lift out faster, more fundamental, fluteier, response a little harder core higher slower, sharper, more principled, a little louder, speech a little duller deeper faster, more fundamental, fluffier, a little quieter, response a little harder Core column tighter more dry and sharp sharpness, quieter, more diffuse, response often faster, with very narrow gaps: slower, more noise further more rough and hard sharpness, louder, clearer, response often slower, with very wide gaps: faster, more scratching Slicing height increase More fundamental, fluffier and slower, harder spitting, less scratching humiliate sharper, more principled and faster, duller spitting, more scratching
 Upper labium press in quintier and more colorful, speech long and hard lift out Fundamental and darker, response short and somewhat softer core higher like above and louder deeper like above and quieter Core column tighter as above and stronger blowing noise further as above and stronger scratchy noise

#### Intonation styles

In the history of organ building there are three main types of intonation:

• Baroque intonation: The aim is to let the pipe speak freely and naturally. In order to be able to show the guidance of individual voices clearly, the address or articulation of the pipe is clear, lively and fast. You look for the point of greatest possible response. Each note retains its own life without leaving the register's characteristics. Intonation aids such as core stitches or beards are only used to a limited extent in order to improve the response and reduce background noise. This preserves the richness of overtones in the pipe.
• Romantic intonation: The aim is to give the pipe a static, powerful tone in order to obtain homogeneous and nuanced registers with which large compositional lines and sound surfaces can be represented. Intonation aids are used to a considerable extent and in a very differentiated manner for tone design. As a result, the response of the pipe is no longer so clear and articulated, its richness in overtones decreases and the registers appear very homogeneous in themselves. To a certain extent, this intonation style has naturally grown over time, as the sound ideal has moved further and further away from the overtone-rich and “steeply” dispositioned baroque organs over many decades.
• Neo-Baroque intonation: This type of intonation emerged with the so-called "organ movement". A sharp tone rich in overtones will be produced with little or no intonation aids, e.g. B. the core stitches, aimed to obtain a transparent sound image for polyphonic music. Since other intonation devices are used than in the Baroque period, the response or articulation of the pipes is indistinct and associated with strong overtone development. The point of greatest possible response is also not reached. Likewise, these intonation means prevent the different types of register groups from merging, as is required for romantic music. What is remarkable about this way of intonation is that it has not grown continuously over time, nor that it simply tries not to copy the baroque style unchanged into another time. Rather, the real style and sound characteristics of historical baroque organs were misunderstood and as a result idealized too extreme.

#### Sound fusion

A sound amalgamation can only be achieved with the right intonation. This must meet three requirements:

• The fundamental tone and the following five partials should be developed strongly. Low cuts and narrow kernels can prevent this.
• High overtones (from the eighth partial) and unharmonic sound components should be avoided. (Inharmonic overtones are a side effect of so-called core - free intonation with filed core slits.)
• Speech noises, such as spitting and hissing precursors, must be minimized.
Expression

With the classic intonation means (core stitches, changing the foot hole, the core gap width and the height of the cut) - depending on the desired sound image of the entire organ - often no satisfactory balance can be found between these requirements and a homogeneous and powerful sound. If a tone with a high cut, strong core stitches and wide core gaps is intoned too fundamentally, it loses its strength and sounds dull. If it is voiced without core stitches, with a lower cut and narrowed core gap, the precursor tones and the high-frequency sound components prevent a closely interlinked, harmonic overtone structure and a homogeneous sound image. High and inharmonic sound components prevent a good sound amalgamation. Hard and bright speech noises disrupt large musical lines. On the other hand, weakly developed middle overtones take away the power and color of the sound. Expressions are therefore a tried and tested intonation tool to control the balance between tonal power and fusion. They act like sound filters: Depending on their size and position, they filter certain overtones and speech noises from the overall sound of a pipe. Other overtones are even more prominent and give the tone a special expression (hence the name expression ). Expression is therefore a typical and important means of intonation for organs in the romantic style in order to achieve the highest possible degree of sound fusion.

### Mood

Tuning slot with tuning roll
Two different tuning horns

Labial pipes are tuned in different ways depending on the design:

• Closed pipes can be tuned by simply sliding the lid.
• Some metal pipes have tuning rings at the top (comparable to an open lid) with which the pipe can be effectively lengthened or shortened.
• Open wooden pipes sometimes have a metal tuning cap. This can be bent more or less obliquely over the mouth by bending.
• A flap is often cut out at the mouth of the pipe. The so-called tuning slot is enlarged or reduced by rolling this flap in or out ( tuning roll , in the case of wooden pipes instead a slider) .
• If the pipe has beards, the beard can also be used for tuning if there is no other way of tuning the pipe. (Example: Dedicated pipes with a soldered-on lid or long pipes that are far away from the vocal channel and that are, as it were, only temporarily tuned by the beards as part of the annual mood.)
• Open metal pipes can also be cut to pitch and therefore do not have an independent tuning device; this is the rule , especially with smaller pipes (from about 12 ′ position). Such pipes can only be tuned with the tuning horn . This is a conical tool with which the pipe is slightly widened or closed at the mouth ( rubbing open and rubbing ). The advantage of this variant is the greater tuning stability compared to tuning rollers or covers (which can shift over time due to gravity and material fatigue, among other things), the disadvantage is the significantly higher material load during the tuning process itself.

The pitch of labial pipes only changes with temperature fluctuations, as these affect the speed of sound in the pipe: The pipes become higher when it is warm, and lower when it is cold. The detuning is around 3.3  cents per degree Celsius, which corresponds to a semitone at 30 ° C. In principle, only the pitch of the voice changes; the pipes remain in a constant mood among each other.

Every 15 to 25 years the pipework has to be dismantled and cleaned, as dust deposits make the mood of the pipes (especially the small labial pipes) difficult or even impossible.

## Lingual pipes (reed pipes)

In the foreground: tongue register
Whistle of tongue

The second group of organ pipes are the lingual or tongue pipe in which the air stream has a metal tongue ( reed offset) in oscillation, and the resulting sound through a sound (cup) is amplified.

The sound of reed pipes is much richer in overtones than that of labial pipes. The construction of the reed pipes is chosen to imitate the sound of brass or reed instruments, in particular that of trumpets, trombones, clarinets, oboes, fanfares and other instruments (shelf, zinc, dulzian, rankett).

The entirety of all reed pipes of an organ is - based on the reed of woodwind instruments - also referred to as reed (s) . Partly also from the snare works mentioned, in reference to the buzzing sound of kurzbecherigen reeds. This term is not used in the written language. Registers with counter-reeds are not known in organ building.

Audio sample: horizontal joints ? / i (470 kB)

There are two ways in which the sound of reed whistles is produced:

• The most common are tongue whistles in which the metal tongue hits a so-called throat . These reed pipes are also referred to as "striking" reeds.
• Reed pipes in which the metal reed swings through a precisely fitting opening, as in the harmonium , are referred to as "through" or "striking" reeds . This type of construction is seldom found in comparison to the "striking" reeds. It was most widespread between 1840 and 1920 and has only been rebuilt occasionally in the last few years. In terms of sound, the "penetrating" voices differ from the striking reed voices mainly in their softer response and a strong, penetrating sound. Typical registers are basset horn , euphon , clarinet (or clarinet ).

### construction

Lingual whistle (German design): (1) attachment or bell
(2)
tuning crutch (3) cup socket
(4) boot
(6) wedge
(7) throat
(8)  tongue
(9) foothole

From a functional point of view, reed pipes are also made up of two parts, but with a different distribution of tasks than labial pipes: The sound is created in the lower part of the pipe (the boot ). This is where the tongue with the tuning device is housed. The upper part (cup) is a hollow body made of wood or metal, which provides resonance and thus amplification and coloring of the sound.

The nut is inserted into the boot from above and the throat and tongue are wedged into this with a small wooden wedge. The throat is a metal tube that is open at the top into the cup and closed at the bottom. When viewed in cross-section, the throat consists only of a larger segment of a circle; the tongue rests on the wide side opening. This is slightly bent up at the lower end.

The tongue is pressed into place on the throat by the end of a sturdy wire (tuning crutch) bent several times . Only the free lower part beyond this point of support of the crutch can vibrate the sound. The crutch is led out of the top of the nut and usually angled again at the top. (This design describes all impact tongues, penetrating tongues are constructed slightly differently.)

### Sound generation

Since the tongue is slightly curved outwards and does not completely close the slot (elongated opening in the throat wall), the air flowing into the boot can pass under the tongue into the throat and further into the cup. This air flow creates (periodically) a negative pressure in the throat, which pulls the tongue onto the slot when the tongue is opened and into the slot when the tongue penetrates. Since the tongue has practically almost closed the slot, the flow of air is interrupted. Now there is no longer any suction effect on the tongue and it can move back again. As this process repeats itself regularly and quickly, an air oscillation arises that we perceive as a sound with the ear.

Due to the way the sound is generated with a vibrating tongue, the length of the bell - unlike the lip whistle - has no direct influence on the pitch, but it does affect the timbre and strength as well as the successful sound generation. The tongue also responds without a bell and in principle with almost all bell lengths. However, just like the body of a lip pipe, the bell has a certain “correct” length for each pitch.

### Mood

If you move the crutch by gently tapping it up or down with the voice iron , the length of the freely swinging area of ​​the tongue changes and with it the pitch. In principle, whistles detune when the temperature changes to the extent that there is thermal expansion of the sound-producing substance. Since the sound in labial pipes is generated by the air itself and the air expands relatively strongly, the detunings are also relatively large. The thermal expansion that the metal tongue of lingual pipes experiences is almost negligible in comparison. For various reasons, however, the reed whistles of a register become slightly out of tune over time.

Temperature fluctuations of a few degrees are enough that the pipes of both types can no longer be combined satisfactorily. In practice, the reed pipes are always tuned, as they represent the minority of the pipe inventory in an organ and because they are easier and more gentle to tune. While a complete tuning of the organ is done annually by the organ builder, the lingual pipes are tuned as required, usually also by the organists themselves.

### Types

Main designs:
(1) open labial pipe
(2) closed labial pipe (wooden construction)
(3) lingual pipe

#### Important elements

The shape of the throat, the thickness and width of the tongue and the shape and length of the beaker influence the sound of a reed whistle. Particularly present in the sound are horizontally arranged reeds such as the Spanish trumpet, but also shelf-like registers, since no other pipes or parts of the organ case stand in the way of the propagation of the sound waves and since the sound is emitted directly (horizontally) into the room.

#### cups

The construction of the cups can be very different. A distinction is made between long or full- cup reeds (i.e. reed registers), in which the cup length is matched to the pitch, and short- cup reeds with a significantly shorter cup.

• Full-length funnel bodies result in a harmonious sound similar to a brass instrument due to their natural, as perfect as possible overtone structure . Typical names are therefore trumpet (16 ′, 8 ′, 4 ′) and trombone (16 ′; less often 32 ′ or 8 ′), but also bassoon (32 ′, 16 ′; not as powerful as a trombone), bombarde (32 ′, 16 ′; usually the loudest reed register in an organ), Clairon (4 ′) and zinc (2 ′ or 1 ′ in the pedal). The length of the attachment depends on the width of the cup and is typically a good 7 'length for an 8' tone. The cup length is often chosen to be slightly larger than it physically results in order to round off the sound.
• Long funnels result in a sound that is very stable. It is possible to lengthen the beaker by about 25% so that it has the length of a labial pipe of the same depth (8 'length for an 8' tone). In this case, one also speaks of the length of a third , since this beaker gauge corresponds to that of a normal-long lingual pipe that sounds a third lower. Examples of this are Tuba mirabilis or French horn . Double bell lengths (about 14 'length for 8' tone) are built, among other things, in the high register of the trompette harmonique , with an 8 'register from about c 1 . In the case of registers with a full cup length, the highest register from around c 3 onwards has twice the cup length, so that the highest register has enough volume of sound compared to the lower registers.
• Half-length funnels are rarely built to produce a specific sound. In particular, 32 'and 16' registers with full cup length per se are in the large and z. Partly also built in the small octave with half-length beakers. This happens either due to a lack of space at the top or, with 16 'manual registers, in order not to let the lowest register appear too voluminous compared to the higher register.
• Combined funnel bodies produce different sounds such as shawm , oboe , English horn (darker than oboe).
• Full length cylindrical bodies give a nasal sound like crumhorn . Physically this results in a theoretical length of 4 ′ for an 8 ′ tone. Cylindrical beakers are also sometimes built a little longer up to about 5 'for an 8' tone in order to achieve a rounded sound. Due to the cylindrical shape of the cup, the even-numbered partials (including the octaves) are omitted.
• With a short beaker, the result is a rasping, very overtone-rich sound like on the shelf or the Vox humana . Many different cup constructions are used for the shelves, which serve to shape the sound; z. B. Cylinder, funnel, cylinder with funnel attachment, cylinder with double cone attachment; all open or partially covered.

(Remarkably, the relationship between design and overtone characteristics is exactly the opposite for labial and lingual pipes. Only wide-opening, funnel-shaped beakers promote the development of all partials.

A wide variety of materials are used to manufacture the cups. Cups are often made of metal, then organ metal, copper, zinc, brass or occasionally tinned iron sheet ("tinplate") is used. But cups can also be made of wood and then have a square cross-section. Such cups are widespread on the shelves (wooden shelves, tendrils), but other reed voices (e.g. trombones and trumpets) are also available in this design.

#### Throat and tongue

Tongue, throat, nut and tuning crutch of a 16 'Dulzian pipe

Throats are usually milled from brass or cast from organ metal, especially in recent times made from certain types of wood. Lead throats have been built, but they tend to deform over time. The groove can be cylindrical or conical (larger diameter at the bottom). The slot can in turn have different shapes. The grooves can also have a lead or tin coating, which can then be reworked (e.g. at Arp Schnitger ). The track of the throat can also be covered with leather ( leather-covered ) to dampen the reed, which makes the sound softer and less overtone. In addition, the throat is differentiated according to the shape of the underside: the so-called German throat is flat at the bottom, the French throat rounded at the bottom. There is also the beveled shuttle throat . All of the parameters mentioned, as well as the width and depth of the throat, each have a certain influence on the sound strength and timbre. The tongues are mostly made of brass. The tuning crutch is usually made of a hard copper alloy (often nickel silver).

### Scale length

As with the labial pipes, a large number of dimensions are decisive for a certain sound pattern that a lingual pipe should produce; there are also scale lengths or scale tables for these. The most important lengths of reed pipes are the dimensions of the tongue (length, thickness, width), the throat and the length and width of the beaker. However, the sound generation (and also the later intonation) of reed pipes is more complex than with labial pipes. While certain lengths of the labial pipe inevitably depend on each other directly or indirectly, this is not fundamentally the case with the lingual pipe, only the length and width of the tongue must necessarily match the throat measurements. A single "clumsy" or improperly chosen scale length (i.e. only one part, concerning one size) can have a clearly negative effect on the overall sound. In order to be able to build “beautiful” reed registers with a high degree of certainty, historical scale dimensions are also being used completely unchanged, i.e. those registers are copied to a certain extent.

### intonation

#### Influencing elements

Lingual pipes can be voiced by strengthening or weakening the curvature of the reed. This changes the sound to a small extent, but above all the volume and response. If there is a lid or other movable device on the cup, this is also used for intonation, but these parts primarily only have an influence on the sound. For a good sound and also for the "functioning" of a tongue, the length of the scale with all its detailed dimensions is of much greater importance than for labial pipes.

#### Throwing of the tongue leaf

There are innumerable possibilities for throwing up. However, two basic types can be identified. Because they are closely connected with the corresponding scale length and a typical sound, one can also speak of the German and French bow.

• The German arc basically follows an exponential course. The curvature of the tongue begins very gradually at the point of contact of the crutch and reaches the strongest curve at the end of the tongue.
• The French bow begins in the same way, but reaches the maximum of the curvature in the area of ​​half to the front third of the swinging part of the tongue. Then the arc decreases again exponentially.

A throwing block and a polishing steel are usually used to design the throw .

#### Bourdon point

As described above, a reed whistle responds with almost every cup or cup length, but there is a very specific cup length for every pitch, which promotes an optimal tone development. If the aim was not to adapt each reed pipe to the corresponding labial pipe, but only to find the right pitch for the given cup length, tuning would be done as follows: The reed pipe is first brought to the pitch of the so-called Bourdon point. To do this, the tone is initially set quite high. Then it is tuned lower until the tone suddenly drops and the sound changes. If the reed is optimally bent, it now sounds fundamentally and less rattling, as if a Gedackt register of the same pitch would sound. If the tone is now tuned even lower, it smashes stronger and stronger, and gradually the fullness (the "bourdon") disappears. The ideal pitch is in this range. At a certain point, about a semitone lower, the timbre changes again, the tone becomes garish. The moment before this change is reached is called the brilliant point.

In practice, not every reed whistle can be tuned on its own. Rather, it must be ensured that each cup is exactly the right length when building or installing and voicing the register, so that the pitch specified by the labial whistle is between the drone point and the brilliant point. A particular difficulty lies in the fact that, as described, the lingual pipes, which are actually not out of tune, are retuned, so the lingual pipe with a beaker of the same length must emit slightly different high tones. If the tone is very close to the Bourdon point, however, experience shows that there is a risk that the mood will change significantly if the room temperature is only a few degrees colder.

Audio samples (tuning the tone f 1 of a pedal trumpet 8 ′):

Votes down ? / i Here you can hear the tipping over into the Bourdon point, at the end the brilliant point is reached.
Vote up ? / i The Bourdon point can be heard clearly.
 tongue raise stronger louder, more fundamental, slower response; The tone jumps into the Bourdon point earlier, then sounds softer and is more stable raise weaker quieter, more overtone, faster response; The tone later jumps into the Bourdon point, then sounds sharper and is more unstable closer to Bourdon point softer, more fundamental, quieter. The tongue is very much dampened by the resonance of the cup. As a result, errors in the arch of the tongue are not so noticeable, and the mood changes less when the temperature changes compared to the labials. The tongue tone is more determined by the cup. closer to the brilliant point sharper, more overtone, louder. The tongue is only very weakly dampened by the resonance of the cup. For a good sounding note, the reed must be bent correctly, otherwise it will clink with a hard metal clink. Due to the weaker influence of the resonance of the cup, the mood compared to the labials changes considerably when the temperature changes. The tongue tone is more determined by the tongue blade.
Schematic drawing of the punch tongue with the “wrong”, turned position of the tongue leaf double-sided (left) and one-sided (right) cubic open
Pre-assembled pipe stick in an organ workshop. He holds the pipes on the wind chest.

Successful intonation of a reed register requires a great deal of experience. Nevertheless, individual pipes in such a register can at times bring even a savvy professional to the edge of his knowledge. That is why there is a saying that applies to organ building at all times: "Schnarrwerk-Narrwerk".

### Turned punch tongue

The reed stops, which cannot be adjusted, were invented by Ernst Zacharias in the 1980s and are thus one of the few new inventions in organ building in recent years. In these reed whistles, a penetrating reed with its frame is mounted at a certain point on the cup in such a way that it is blown on from the side from which the tongue cannot normally be made to vibrate by blowing. But it works in conjunction with the cup and its resonance properties. The air column and tongue interact in such a way that a stable sound is created. This principle gives the Zacharias tongue whistles the peculiarity that they behave exactly like lip whistles when temperature changes, i.e. they do not get out of tune with them. Another advantage: they can be blown strongly or weakly without changing their pitch in the least. Only the volume of your tone is affected by this: Your tone can swell up and down over an extremely large dynamic range through changes in wind pressure. The extremely simple construction is also advantageous, as the throat, head, boots and crutch of the conventional reed voices are no longer necessary. The pipe construction is similar to a wooden labial pipe with a “frog”, with the tongue mounted under the frog instead of a labium. Two registers of this type are located in the Marktkirche Poppenbüttel (clarinet 8 ', saxophone 8') and the organ of the Friedenskirche Eckenhaid (clarinet 8 ') has one register. This principle is also used in the Khaen , an Asian mouth organ.

## Offset and excess length

• Depending on the specific installation situation, it may be necessary to reduce the required installation height for pipes by making them cranked . The pipe body is mitred once or twice at an angle of 90 degrees. The pipe runs horizontally over part of its total length or even turned downwards again.
• In the case of lingual pipes with metal cups, it is possible to "wind up" the cups in the lower area by means of multiple cranks by a total of 360 degrees. In appearance this cup resembles a brass instrument.
• A special form is the Spanish crank, also called the Haskell crank after its inventor William E. Haskell (Estey Organ Company, patent in 1910), but the term Spanish construction would be better , as the pipes are not angled (i.e. cranked in the real sense) instead, a tube closed at the top is hung into the open pipe, which makes the pipe sound deeper (like a closed pipe), but retains the overtone spectrum of an open pipe. There are several different variants for metal and wooden lip pipes of this type and also for reed pipes. According to rumors, this design was already known in Spain in the 18th century. It works best with deep pipes and is more suitable for pipes from the string section.
• A pipe body can also intentionally be built longer than acoustically necessary ( excess length ). For optical reasons, this often happens with prospectus pipes . The swinging column of air is reduced to the correct length by cutouts in the back of the pipe.

## Special forms

In principle, the organ's sound is always generated by labial or lingual pipes, for which all the principles described above apply. In rare cases this does not apply. A distinction can be made here as to whether the pipes in question are permanently assigned to the tones of the keyboard or whether specific tones or sounds are to be generated independently.

Associated with the pipes of the keyboard:

• Double-tone whistle - It has controllable flaps which, similar to a recorder, allow the production of several tones per pipe.

Other registers that are permanently assigned to the keyboard tone sequence do not generate their tones by whistling, e.g. B. the carillon .

Some effect registers have pipes that are not assigned to the keyboard. For example:

• Nightingale - Several tall pipes are attached turned by 180 ° and their opening ends in a water container. The pitch changes due to the movement of the water when the whistles sound, and the sound resembles the call of a nightingale.
• Cuckoo Call : Whistles that imitate the singing of a cuckoo.

Other registers that are independent of the keyboard (e.g. cymbal stars ) do not generate their tones by whistling either.

## literature

• Wolfgang Adelung: Introduction to organ building. 2nd revised and expanded edition. Breitkopf & Härtel, Wiesbaden 1991, ISBN 3-7651-0279-2 (2nd edition, 2nd revised and expanded edition, ibid 2003).
• Hans Klotz : The book of the organ. About the nature and structure of the organ work, organ maintenance and organ playing. 14th edition. Bärenreiter, Kassel et al. 2012, ISBN 3-7618-0826-7 .
• Axel Leuthold: The calculation bases of the organ pipe scale in the Renaissance and Baroque. Methods for their reconstruction and systematisation (= monographs on organ documentation. Vol. 7, 1–2 = International Working Group for Organ Documentation, (IAOD). Publication Vol. 7, 1–2). 2 volumes. Pape Verlag Berlin, Berlin 2004, ISBN 3-921140-63-3 (also: Freiburg, Schweiz, Univ., Diss., 2002).
• Klaus Winkler (ed.): The physics of musical instruments. Spectrum of Science, Heidelberg 1988, ISBN 3-922508-49-9 .

Commons : Organ pipes  - collection of images, videos and audio files
Wiktionary: Organ pipe  - explanations of meanings, word origins, synonyms, translations

## Individual evidence

1. a b J. Angster, A. Miklós: Linear and non-linear wall vibrations of open cylindrical organ pipes. 2003, accessed February 24, 2020 .
2. Angster, Judit; Rucz, Péter; Miklós, András: Acoustics of organ pipes and future trends in the research. 2017, accessed on February 24, 2020 .
3. Helmut Langenbruch : Elementary organ and registration. Ev.-luth. Landeskirche Hannover, October 1, 1992, p. 5 , archived from the original on January 1, 2014 ; accessed on January 1, 2014 .
4. Compensation of the organ pipes . 1829. A detailed article by Prof. Weber on lingual pipes with penetrating tongues. Full text on Wikisource
5. Preview of the book: Urania. 1846, p. 22 ( limited preview in Google Book search).
6. ^ Mathias Jung: The Zacharias tongue in Eckenhaid. http://www.orgelbau-rohlf.de/ , accessed on September 20, 2018 .
7. Information on the double-tone whistle made by Orgelbau Vier
 This version was added to the list of articles worth reading on November 28, 2006 .