64 Foot Organ Pipe Frequency

A brief guide to the Pipe Organ

~ past Geoffrey Redman

Photo of lots of pipes

On this page:~

And so how does an organ piece of work?
How do the pipes work?
Length of pipes
What are Stops?
What are Ranks?
Dissimilar types of action
Bibliography

So how does an organ work?

In gild for it to work, an organ requires current of air~ and lots of it! Present, the air current in the bellows is supplied past electric blowers but in days of old, bellows had to be pumped by hand. The current of air from the bellows is controlled by the activity, that determines which pipes are allowed to speak, and which pipes are to remain silent. Since it is the length of a pipe that determines the pitch of the sound it makes, there must be at least one pipe for every annotation on the keyboard. To get the different colours of audio and varying degrees of loudness, there needs to be a lot of pipes.
There are many, many different types of organ piping and each type has its own timbre and name. For example Stopped Diapason, Lieblich Flute, Dulciana and Chief. Such a vast number of varying designs has come well-nigh through experimentation and a desire to emulate other musical instruments like the Trumpet or Oboe, Flute or Violin. The result is that the organ is both the loudest and the quietest of all instruments. However, all organ pipes belong to one of ii families~ the Flue pipes and the Reed pipes. An case of the sound produced by a reed pipage is the Trumpet. An example of the sound produced by a flue pipe is the Flute.
There are many other variables that command the sound other than the pattern of pipage. For example the wind pressure; the materials used in construction and fifty-fifty the fabric of the building in which the organ is installed.

How do the pipes work?

As mentioned above, there are ii main families of organ pipes~ Flue pipes and Reed pipes. Here, we wait at a simple Flue pipe.
Wind enters the pipe at the Tip (a) and fills the Foot of the pipe (b). Since information technology is under pressure level, the current of air is forced through the narrow gap chosen the Flue or Air current-way (d) between the Languid (e) and the Lower Lip (c). The thin sail Diagram of a Flue pipe

of air which leaves the Flue, rushes across the Mouth of the pipe (f) and flows past the front of the Upper Lip (g) into the room. This flow of air across the Mouth pulls air from inside the Body of the pipe (h) along with it, out into the room then the cavalcade of air within the Trunk of the pipe, which until now has been at rest, begins to travel down. At this point, there is a big amount of air leaving the Mouth of the pipe. There is the air coming from the Foot (b) together with the air from the Body (h).
The air does non continue behaving in this manner for very long considering as the air column moves downwardly, it creates a depletion of air molecules at the top of the pipe. When the force of the depletion becomes greater than the force of the air menses from the Flue, the cavalcade of air inside the Body stops moving downwards and begins ascending. As the air column moves dorsum up the piping, a depletion of air molecules now develops at the Mouth and so the air coming from the Flue, which until now has been flowing across the Oral cavity and into the room, is sucked back into the Body of the pipe to maintain an fifty-fifty air force per unit area. At this point, in that location is no air leaving the Oral fissure of the pipe, in fact some air from the room may even be drawn in through the Mouth. And and then we render to the outset of the wheel. It is the movement (oscillation) of air molecules upwards and down the Trunk of the pipe that produces the sound waves.

Length of pipes

The pitch of the sound produced is determined past the length of the body of the pipe~ just equally the pitch of a note made by a stringed musical instrument is determined by the length of the string hit or plucked. A short string will create a higher pitch than a long string~ a short pipe will create a college pitch than a long pipage. So the longer the pipe, the lower the notation; the shorter the pipe, the higher the note.
Photo of some Reed pipes

Pitch tin can be expressed in terms of the frequency of the vibrating cavalcade of air in the pipe. Centre C on a piano has a frequency of near 256 Hertz (cycles per 2nd) and to produce the aforementioned pitch on an organ, a ii pes organ pipe would be required. As it happens, if the length of a pipage is doubled, the frequency is halved and the pitch goes down an octave. So the pitch of a 4 pes pipe will exist Tenor C and an 8 foot pipe volition produce a Bass C. Going the other style, a 1 foot pipage will produce a Treble C and a ½ foot pipe volition produce a Top C and the octave higher up that is a 3 inch pipe.
The longest piping in an organ is usually in the pedal department and on most organs is 16 foot in length. Cathedral organs usually accept 1 or two 32 foot ranks, the 32 human foot pipes having a frequency of just xvi Hertz! The longest pipes in existence are 64 foot long, but these enormous pipes are few and far betwixt. Equally far every bit I know, there are only two organs in the world having pipes that are actually 64 feet in length. The famous Hill organ in Sydney Town Hall which has a 64 foot Contra Trombone and the colossal Midmer-Losh organ in Atlantic Urban center which has a 64 foot Diaphone-Dulzian.
Just to misfile things a little, some pipes are stopped which ways that the top is blocked off by a stopper. This has an harmonic event and the sound heard from a stopped pipe is an octave lower than its open up counterpart. For case, when it says Stopped Diapason viii' on the Stop Knob, the longest pipe is actually only 4 foot long.

Close-up photo of some very small pipes

What are Stops?

The Stops are used to stop the air from flowing through the pipes. The Stops are part of the activity that controls which pipes are allowed to speak and which are to remain silent. The Stop action links the Stop Knobs in the Console to the Sliders in the Soundboard. The bodily Slider is a piece of woods with holes drilled in it to line up with the feet of the pipes. The Slider can motion either in or out~ when it is in, the holes don't line up with the pipes and the air is stopped from getting through. When it is pulled out, the holes do line up and air is immune to laissez passer through to the pipes. There has to be one Stop for each rank of pipes.
Without organ Stops, whenever a fundamental is pressed on the keyboard, every pipage above that note on the Soundboard would speak! Before organ Stops were invented, that is exactly what happened. This chorus of pipes for every notation on the keyboard is called "Blockwerk".
Organ Stops are identified at the Console by the names of the pipes that they command. And then the Finish that controls the Open Diapason rank has "Open Diapason" inscribed on the Stop Knob. Also inscribed is a number that corresponds to the length in feet of the longest pipe within that rank, then that the organist has some idea of the pitch. If the pipes are stopped, the longest piping won't actually be as long as it says! Information technology will be one-half the length, because a stopped pipage sounds an octave lower than its open counterpart. However, the length inscribed on the Finish Knob is always the equivalent open up length.
Many people use the term "Stops" to identify the dissimilar sounds produced past an organ or to describe a item ready of pipes. For example, "The trumpet End is out of tune once again!", or "That'southward a prissy Stop, what's information technology called?" This is not strictly correct because it is the pipes that make the sound, the Stops but control which pipes are allowed to speak.

What are Ranks?

The pipes in an organ are grouped together in rows or ranks according to the particular sound that the pipes make. Each rank has enough pipes for every notation on the keyboard and and so there are unremarkably 61 pipes in a rank.
Photo of some Nazard pipes

Ranks are identified by the length of the longest piping in the rank. For example, a rank of Open Diapasons (8 human foot) volition hold pipes varying in length from a couple of inches to 8 feet. In this example, the lowest note is produced past the viii human foot pipe and so this rank is referred to as the 8 human foot Open Diapason rank. Every bit already mentioned, it is this name that appears on the Stop Knob in the Panel. A Terminate Knob with "Principal 4" inscribed, controls the 4 foot Master rank.
Sometimes pipes are named according to the interval between them and the viii human foot pitch. For instance, a 2 pes Flageolet produces a annotation that is fifteen notes college up the scale than an 8 foot piping (a interval of a fifteenth). This ways that when a middle C on the keyboard is pressed, with simply the Flageolet End out, the note that is heard is actually a superlative C (two octaves higher). So it is called a Fifteenth.
The Nazard pipes sound a twelfth college than the notation that is being played and the inscription on the End Knob will read "Nazard" or "Twelfth". If a length is inscribed, it would be "two 2/3" because that's the length of the longest pipe in the rank (2 pes 8 inches). If a Nazard middle C is pressed on the keyboard, a treble One thousand is what we would actually hear! The Nazard is referred to equally a Mutation Terminate which means that information technology sounds odd when played on its ain. All the same, when played together with some other rank, it can enhance the colour of sound.

Different types of activeness

The action is the organisation that is used to allow the organist to control the musical instrument. There are two parts of an organ that are controlled by the activeness. The first is the Stops and the second is the Pallets. In some organs the type of action used is the aforementioned for everything and in other organs there might exist one blazon of action for the Stops and another type of action for the Pallets.

Tracker action

Tracker activeness, or mechanical activity as information technology is ofttimes called, is the oldest type of action. It does not require whatever electrical appliance for information technology to operate because the link between the organist and the Pallets is completely mechanical. A series of levers and connecting rods transfers the movement from the keys to the Pallets.

Electropneumatic action

This type of action uses electric current between the manuals and the Soundboard and then pneumatic motors to actually open the Pallets. Pressing a central on the keyboard completes an electrical circuit and the corresponding solenoid is energised. The solenoid releases air from a pneumatic motor which opens the Pallet for that note.

Bibliography

BICKNELL, Stephen. The history of the English organ. Cambridge : Cambridge University Printing, 1996.

BONAVIA-HUNT, Noel. The church organ. London : William Reeves, 1920.

BONAVIA-HUNT, Noel. Modern organ stops: a applied guide to their classification, construction, voicing and creative use with a glossary of technical terms relating to the scientific discipline of tone-product from organ pipes. London : Musical Stance, 1923.

CLUTTON, C. and NILAND, A. The British organ. London : Batsford, 1963.

DICKSON, W. Due east. Applied organ-building. Portsmouth : Bardon Enterprises, 1997.

NORMAN, Herbert and NORMAN, John. The organ today. London : Barry and Rockliff, 1966.

SUMNER, William. The organ. tertiary Ed. - London : Macdonald, 1962.

THISTLETHWAITE, Nicholas and WEBBER, Geoffrey. The Cambridge companion to the organ. Cambridge : Cambridge University Press, 1998.

WHITWORTH, Reginald. Organ stops and their use. London : Pitman, 1951.

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