Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Organ pipe
open-in-new
<h2 id="construction">Construction</h2> <h3>Materials</h3> <p>Organ pipes are generally made out of either <a href="/facts/Metal/PT8hNX6R">metal</a> or <a href="/facts/Wood/z13NpHPl">wood</a>. Very rarely, <a href="/facts/Glass/hezRsAGf">glass</a>, <a href="/facts/Porcelain/deuLm3sb">porcelain</a>, <a href="/facts/Plastic/Kla5QItn">plastic</a>, <a href="/facts/Paper/FUETwwKV">paper</a>, <a href="/facts/Papier-m%C3%A2ch%C3%A9/m9TAJ3JY">Papier-mâché</a>, or even <a href="/facts/Rock_(geology)/FXCJkmop">stone</a> pipes may be seen. A <a href="/facts/Las_Pi%C3%B1as_Bamboo_Organ/guueICN9">historical organ in the Philippines</a> has pipes made exclusively of <a href="/facts/Bamboo/wGPJ2cEA">bamboo</a>. </p> <h4>Metal</h4> <p>Metal pipes are usually made of <a href="/facts/Lead/EYljasJN">lead</a>; for increased rigidity it is <a href="/facts/Alloy/I7w7WQWR">alloyed</a> with <a href="/facts/Tin/obW9mqc3">tin</a> along with trace amounts of <a href="/facts/Antimony/YsA7lVgT">antimony</a> and <a href="/facts/Copper/I8PEE8oX">copper</a>. The percentage of each metal in the alloy influences the characteristics of the resulting pipe. A high proportion of tin results in a slightly brighter colour (optical colour, not timbre). In addition, high amounts of tin give a gleaming and long-lasting polish, which may be desired if the pipe is clearly visible. The cost of each metal is also a factor, as tin is more expensive than lead. Cost considerations may also lead to the use of the inferior rolled <a href="/facts/Zinc/80b1qgk3">zinc</a> especially for the lower tones that take a lot of material. In addition, pipes have been made of many metals, including <a href="/facts/Copper/I8PEE8oX">copper</a>, <a href="/facts/Aluminium/7wmR8jYE">aluminium</a>, <a href="/facts/Gold/1znknojp">gold</a> <a href="/facts/Electroplate/HbKf0SBb">electroplate</a>, <a href="/facts/Silver/xXe41BGg">silver</a>, <a href="/facts/Brass/pe8EHk6x">brass</a>, and <a href="/facts/Iron/QK1JYy8E">iron</a>. </p><p>Metal pipes are generally made by first <a href="/facts/Casting_(metalworking)/7mMSBWTs">casting</a> the desired <a href="/facts/Lead/EYljasJN">lead</a> alloy onto a long flat surface. Once the metal cools, it is cut into pieces, which are then rolled into shapes around molds called <a href="/facts/Mandrel/KUxSyG2d">mandrels</a> and soldered together. Thus, the cross-section of a metal pipe is usually circular. The low melting point, solderability and malleability of the organ metal makes the construction of pipes relatively easy. </p> <h4>Wood</h4> <p>The body of a wooden pipe can be made of either a coniferous wood (softwood) or hardwood, although the lower section of the pipe (comprising the metal foot (on some pipes), cap, block and mouth) will nearly always be made from hardwood to provide a precise edge for the pipe's mouth. Using screws and glue, the pipes are assembled from wooden pieces of various shapes and sizes. In contrast with the circular cross-section of a metal pipe, the cross-section of a wooden pipe is most commonly square or rectangular. </p> <h4>Glass</h4> <p>Glass pipes have been created using <a href="/facts/Warm_glass/WzHjTFdC">warm glass</a> and <a href="/facts/Stained_glass/oUCut2Mc">stained glass</a> techniques by <a href="/facts/Xaver_Wilhelmy/M3n458H6">Xaver Wilhelmy</a>. Three Wilhelmy glass ranks exist in the United States, two in a private collection in West Virginia and one in a private collection in Virginia. The image at left shows the Wilhelmy American Flag Glass Pipe Organ that was created as a part of a Memorial Proposal for Ground Zero after the events of September 11, 2001.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a> </p> <h3>Shapes</h3> <p>The bodies of organ pipes are generally made in three shapes: cylindrical, conical, or rectangular. Cylindrical pipes are simple <a href="/facts/Cylinder_(geometry)/0wQPPr3k">cylinders</a>, while conical pipes are in the shape of a tapering or expanding <a href="/facts/Cone_(geometry)/2c9GIzYD">cone</a>. Rectangular pipes form <a href="/facts/Cuboid/eLLKX4rh">cuboid</a> shapes with either a <a href="/facts/Square_(geometry)/JHJeMvmL">square</a> or <a href="/facts/Rectangle/mdLfIGKA">rectangular</a> cross-section when viewed from above. There are some irregular shapes as well: the Flûte triangulaire, for example, has a <a href="/facts/Triangle/cRXUwsMn">triangular</a> cross-section when viewed from above. In addition, a cylindrical or rectangular pipe can be <i>tapered</i>: that is, it can be made to be wider at the bottom than at the top. The internal shape of the pipe is a major factor in tone color. </p><p>The end of the pipe opposite the reed or mouth may be either open or closed (also known as <i>stopped</i>). A <a href="/facts/Closed_tube/BExhpHGK">closed flue pipe</a> with a uniform cross-section sounds an octave lower than a similar <a href="/facts/Open_tube/BExhpHGK">open pipe</a> of the same length. Also, such an open pipe produces a tone in which both the even-numbered and the odd-numbered <a href="/facts/Harmonic_series_(music)/PdElIrxL">partials</a> are present, while a stopped pipe, such as a <a href="/facts/Gedackt/6LtSI3cg">gedackt</a>, produces a tone with odd-numbered partials. The tone of a stopped pipe tends to be gentler and sweeter than that of an open pipe, though this is largely at the discretion of the voicer. </p><p>Certain organ pipes are also mounted horizontally in the shape of a trumpet horn so as to project the sound farther. These pipes are known as <a href="/facts/En_chamade/AcvAX80u">en chamades</a>. However, when such a commanding tone is desired but it is impossible to mount an en chamade on the case, a hooded reed is used. This type of pipe stands vertically and has a 90-degree bend at the top which acts to project the sound outward in the same way an en chamade does, but can be placed in the interior of an organ.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> </p> <h2 id="pitch">Pitch</h2> <p class="note">Further information: <a href="/facts/Organ_stop/CmmksFqo">Organ stop § Pitch and length</a></p> <p>The pitch produced by an organ pipe is determined in two fundamentally different ways. For a reed pipe it is determined mainly by the mechanical properties of the reed and the length of the protruding part. For the flue pipes it is determined by the shape of the air column inside the pipe and whether the column is open at the end. For those pipes the pitch is a function of its length, the wavelength of the sound produced by an open pipe being approximately twice its length. A pipe half the length of another will sound one <a href="/facts/Octave/RA4gWvkV">octave</a> higher. If the longest pipe, C, is 8 feet (2.4 m) in length, the pipe one octave higher will be 4 feet (1.2 m) long, and two octaves above (middle C) will be 2 feet (0.61 m) long. A closed (stopped) pipe produces a sound one octave lower than an open pipe. For example, a stopped pipe 4 feet (1.2 m) long will produce the same pitch as an open pipe 8 feet long: two octaves below middle C. </p><p>The nomenclature of a rank of pipes is based on the size of an open pipe that would produce the same pitch, regardless of the type or size of the actual pipes in the rank. For example, a rank of open pipes labeled as 8′ (pronounced "eight-foot") would have a pipe for C two octaves below <a href="/facts/Middle_C/FdvRz0zL">middle C</a> that is approximately 8 feet long. An 8′ stop is said to sound at "unison pitch": the keys on the organ console produce the expected pitch (e.g. the key for middle C causes a middle C pipe to speak), like a piano. In a rank of stopped pipes, the lowest pipe is 4 feet in length but sounds at unison pitch—that is, at the same pitch as an 8′ open pipe—so it is known as an 8′ stop. Reed pipes are also labeled the same as that of an open pipe with the same pitch, regardless of the actual length of the pipe. </p> <h2 id="varieties">Varieties</h2> <h3>Flue pipes</h3> <p class="note">Main article: <a href="/facts/Flue_pipe/gdtsNQ88">Flue pipe</a></p> <p>The sound of a flue pipe is produced with no moving parts, solely from the vibration of air, in the same manner as a <a href="/facts/Recorder_(musical_instrument)/6PegJmIe">recorder</a> or a <a href="/facts/Whistle/UIbmhlwN">whistle</a>. Wind from the "flue", or windway is driven over an open window and against a sharp lip called a <i>Labium</i>. By <a href="/facts/Bernoulli%27s_principle/Y7urHvPr">Bernoulli's principle</a> this produces a lower pressure region just below the window. When the <a href="/facts/Vacuum/BTk3goyV">vacuum</a> under the window is large enough, the airstream is pulled under the Labium lip. Then the process works in reverse, with a low pressure region forming over the Labium which pulls the airstream to the other side again. This 'fluttering' airflow creates high and low pressure waves within the pipe's air column. A high and a low pressure wave form a single "cycle" of the pipe's tone. (See <a href="/facts/Wind_Instrument/w1af9f1t">Wind Instrument</a>.) </p><p>Flue pipes generally belong to one of three tonal families: <i>flutes</i>, <i>diapasons</i> (or <i>principals</i>), and <i>strings</i>. The basic "foundation" (from the <a href="/facts/French_language/qe1DnaQh">French</a> term <i>fonds</i>) sound of an organ is composed of varying combinations of these three tonal groups, depending upon the particular organ and the <a href="/facts/Organ_literature/UgstVbn3">literature</a> being played. </p><p>The different sounds of these tonal families of pipes arise from their individual construction. The tone of a flue pipe is affected by the size and shape of the pipes as well as the material out of which it is made. A pipe with a wide diameter will tend to produce a flute tone, a pipe with a medium diameter a diapason tone, and a pipe with a narrow diameter a string tone. A large diameter pipe will favor the fundamental tone and restrict high frequency harmonics, while a narrower diameter favors the high harmonics and suppresses the fundamental. The science of measuring and deciding upon pipe diameters is referred to as <i><a href="/facts/Organ_flue_pipe_scaling/uIDMonIY">pipe scaling</a></i>, and the resulting measurements are referred to as the <i>scale</i> of the pipe. </p> <h3>Reed pipes</h3> <p class="note">Main article: <a href="/facts/Reed_pipe/d90nIuMg">Reed pipe</a></p> <p>The sound of a reed pipe is produced by a beating <i><a href="/facts/Reed_(music)/uCu3W3pQ">reed</a></i>: wind is directed towards a curved piece of <a href="/facts/Brass/pe8EHk6x">brass</a> (the reed). A partial vacuum is created by higher velocity air flowing under the reed which causes it to be pulled closed against a hard surface called the <i>shallot</i>. This shuts off the vacuum and allows the reed to spring open again. A tuned <a href="/facts/Resonator/NjC413Gn">resonator</a> extends above this assembly and reinforces the sound produced. The principle is the same as that of the orchestral <a href="/facts/Clarinet/57a45Ia7">clarinet</a>. The pitch of a reed pipe is determined primarily by the length of the reed but the volume of air in the resonator supports that frequency. Most reed pipes have a slide to adjust the vibrating length of the reed to fine-tune it. Because of the precision required in the making of the vibrating reed, resonator pipe and its accompanying parts, reed pipes are more complicated to manufacture than flue pipes. </p><p>By altering any of several parameters (including the shape and volume of the resonator, as well as the thickness and shape of the reed), a reed pipe can produce a wide variety of tonal colors. This allows reed stops to imitate historical musical instruments, such as the <a href="/facts/Crumhorn/qcXhBXBV">krumhorn</a> or the <a href="/facts/Regal_(musical_instrument)/fpRB13N8">regal</a>. Because the resonator is partially stopped/closed by the reed, odd-numbered partials/harmonics are dominant (in the hollow tones of Krumhorn and Clarinet stops, for example). If the resonator pipe expands outward to conical, the geometry allows the production of both even- and odd-numbered partials, resulting in the fuller tones of Trumpet and Oboe stops. </p> <h3>Free reed pipes</h3> <p>These are quite uncommon; see <a href="/facts/Reed_pipe/d90nIuMg">"Free reeds" in the "Reed pipe" article</a>. </p> <h3>Diaphone pipes</h3> <p>The diaphone is a unique organ pipe. Uncommon in church and concert pipe organs, they are quite common in Theatre Organs. Invented by <a href="/facts/Robert_Hope-Jones/nExWEQIG">Robert Hope-Jones</a> around 1900, it has characteristics of both flue pipes and reed pipes. The pipe speaks through a resonator, much like a reed pipe, but a spring-loaded <i>pallet</i> instigates the vibration instead of a reed. Possessing a powerful bass groundtone, the pipe is generally made of wood and can be voiced at various wind pressures. The diaphone is usually found at 16' and 32' pitches, however there are a few examples of 8' diaphones. There are two 32' Diaphones in Philadelphia's <a href="/facts/Wanamaker_Organ/A6heh8dt">Wanamaker Organ</a>, and a full-length 64' Diaphone-Dulzian is installed in the <a href="/facts/Boardwalk_Hall_Auditorium_Organ/8l2VUaMb">Boardwalk Hall Auditorium Organ</a> in <a href="/facts/Atlantic_City/qFbBT6Ek">Atlantic City</a>. </p><p>The Diaphone pipes are used for the bottom 12 or 18 notes of the 16' Diapason rank, and also for its bottom 32' octave, on those few Theatre Organs that go that low. </p><p>Hope-Jones also developed an imitative version of the diaphone called the <i>diaphonic horn</i>, which had a more reed-like quality than the diaphone and was voiced on lower wind pressures. <a href="/facts/Wurlitzer/bVJ1vYcc">Wurlitzer</a> built a version of the diaphonic horn for their <a href="/facts/Theater_organ/LvFbXITJ">theater organs</a> at 32' and 16' pitches with huge wooden resonators as extensions of its Diaphonic diapason, and at 16' with metal resonators as an extension of its smaller-scale Open diapason. The <a href="/facts/Austin_Organs,_Inc./jyQqxH7t">Austin Organ Company</a> also developed a metal diaphone at 16' pitch known as a Magnaton. Due to its penetrating tone, a <a href="/facts/Diaphone/qmu1w7n6">diaphone-type horn</a> has also been used in <a href="/facts/Foghorn/2bxGcGNG">foghorns</a> and fire signals. </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Tibia_(organ_pipe)/oTJ3sWMQ">Tibia (organ pipe)</a></li> <li><a href="/facts/Tone_hole/AMETNGzh">Tone hole</a></li></ul> <h2 id="external-links">External links</h2> <ul><li> Media related to Organ pipes at Wikimedia Commons</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"World Trade Center Site Memorial Competition". Archived from the original on 2013-10-05. Retrieved 2013-10-04. <a href="https://web.archive.org/web/20131005054014/http://www.wtcsitememorial.org/ent/entI=683568.html" target="_blank">https://web.archive.org/web/20131005054014/http://www.wtcsitememorial.org/ent/entI=683568.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>"Pipe Construction". Archived from the original on 2019-03-03. Retrieved 2019-03-13. <a href="https://web.archive.org/web/20190303080739/http://faculty.bsc.edu/jhcook/orghist/works/works19.htm" target="_blank">https://web.archive.org/web/20190303080739/http://faculty.bsc.edu/jhcook/orghist/works/works19.htm</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> </ol>