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 = ¹ ⁄ ₄ * slice width = ¹ ⁄ ₄ * 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.

Changes and reactions of open labial pipes
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
Foothole	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
Upper labium	lift out	faster, more fundamental, fluteier, response a little harder
core	higher	slower, sharper, more principled, a little louder, speech a little duller
core	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
Core column	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
Slicing height	humiliate	sharper, more principled and faster, duller spitting, more scratching

Changes and reactions of covered labial pipes
Upper labium	press in	quintier and more colorful, speech long and hard
Upper labium	lift out	Fundamental and darker, response short and somewhat softer
core	higher	like above and louder
core	deeper	like above and quieter
Core column	tighter	as above and stronger blowing noise
Core column	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 ¹ ⁄ ₂ ′ 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 ).