What is the pipe organ?

Anyone who has met me would know in a very short amount of time that I am very passionate about the pipe organ. Why? It’s my instrument, and my world. (Might as well just say it as it is..)
I bring a FAQ regarding the pipe organ and common misconceptions.
How do pipe organs sound at different pitches?
The length of pipes causes sounds to either be lower or higher. In pipe that use reeds, the length has less to do with it, and more to do with the tuning position of the reed.

Are organ pipes always vertical?
No. Pipes can be mounted just about any way imaginable, except for the heaviest of pipes which will not support themselves easily (pipes are made out of a tin and lead alloy, which is very heavy). A feature often found is for trumpet pipes to be mounted horizontally at the front or back of a room. Of course, most pipes in an organ will be vertically placed.

Are the pipes at the front of an organ real?
It depends. Often, many organs are built with fake pipes showing, and all the real pipes are in chambers better allowing the organist to control the volume. Some organs have all the pipes exposed, some have none.
Some organs have real pipes that have been decoratively painted as well.

How is the volume of an organ controlled?
By opening and closing panels to a pipe chamber, or by selecting more or less stops. Pipes are placed in chambers, the amount of individual chambers varies from organ to organ. There are usually panels which open and close, controlled by a pedal (kind of like a gas pedal in a car) to allow more or less sound out of the chambers. The moving panels are usually covered by fancy

Image via Wikipedia

grills to prevent distraction.
Many people believe that the volume of an organ is varied by air pressure, however this is not the case. It is indeed incredibly wrong, as varying the air pressure affects the actual sound quite a bit, changing the pitch and timbre of the instrument.

How fast is the response of an organ?
Depends on the organ and action. Lots of factors play into the response time of an organ. Not to say that they are slow, but some organs have a slight delay. There are many factors that play into this. For one, the organist is often placed far from the pipes and the sound must travel. Second, the amount of air pressure affects how quickly the pipes are supplied with air. Third, the action of the organ, and the process of getting the air to the individual pipes after pressing a key plays greatly into the speed. Some organs use a mechanical connection which move a pallet valve and channel into the pipe, whereas some use electric or even digital connections to communicate a component for an individual pipe to supply or stop air.
Many people say that organs are easily outplayed, and although some can be, this is often not really the case.
Organs with pneumatic actions are often said to be sluggish, especially when placed a great distance from the pipes.
Electro-pneumatic organs and mechanical action are typically fast.
Organs which use MIDI to transmit data of keys being pressed to a computer are often said to be slow, but solid state systems and other non-midi systems are typically quite speedy.

What kinds of instruments do organs imitate? How do they imitate different voices?
Organs are peculiar in that they have switches, buttons, tabs, or pull-knobs which allow you to simply select “ranks” like the trumpet/trompette, or the flute/flote. The actual imitative sounds are far too many to list — they include ancient and modern instruments depending on the kind of organ you are looking at. A theater organ contains modern orchestral sounds (tuba, clarinet, trumpet, flute, violin, &etc.) whereas a classical pipe organ has more historical sounds (trompete, sesquiltra, gamba, and other things I care not to remember how to spell).
A voicer could answer the question of how an organ imitates voices in a more technical way, but in essence pipes are very specifically shaped to produce specific sounds. If you look at an organ tuba or trumpet pipe, you may seem resemblance of the instrument they imitate. The mouth of a flute or string pipe (the opening near the bottom) is often shaped, contains bridges or sides, and has specific cuts that greatly change the sound emitting from them.

How does a organ have “strings” like violin?
Yes. When you see organs with stops like violin, viol, and the likes (or in classical pipe organs, salicional), there are pipes in the organ which have a similar quality of sound as that of the instrument they are named after. Of course, if you play these stops, they don’t really sound exactly like a violin or other string instrument, but you might notice some similarities.

What is the difference between a classical organ and a theater organ?
The functionality. I could write an entire article on this (and probably will). Classical pipe organs are better suited for playing classical music specifically. Theater organs are equipped to accompany silent films with special effects such as drums, bird boat and train whistles, police sirens, gongs, and percussive instruments such as the xylophone, glockenspeil, piano, “harp”, &etc. Theater organs typically have a higher wind pressure allowing them to be a bit louder, and have a distinctive and dramatic tremulant. Theater organs can beused for classical (some would disagree), but classical organs generally do not

Theater organ. Image via Wikipedia

lend to theater music as well (once again, some would disagree).

How is reverb of an organ made?
The acoustic space the organ speaks into. The acoustic space that an organ is placed in is the 100% direct result of the reverberation. Organs in small rooms with carpet and cushy chairs will seem acoustically dead, while organs speaking into large spaces with hard floors walls and furniture will have a lively reverberation effect. The importance of the acoustic space should be clear.
Digital organs and even older non-digital analogue organs often have reverb as a feature.

How do organs have a tremulant or a vibrato effect?
There are two ways. Many organs vary tremulant effect by varying the wind pressure at a high speed. Some organs, although this is less common, may vary the tremulant effect by rotating panels near the pipe to reflect back some sound, but not all.

How does one tune an organ?
By shortening or lengthening the pipe (there are collars to extend or shorten the pipe). In reed pipes, the pipes are tuned by moving the reed up or down.

How many keyboards does an organ have, and why are there so many?
This depends on the organ. In organs, a keyboard is called a

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“manual”. The funny answer is that if the first keyboard fails, you have a backup. The real answer is that different sounds can be accomplished by playing the different manuals. For example, on one manual you could have a trumpet (which is very loud and flashy) with some other things, and a soft registration with flutes on another manual. Now, play the left hand on the quiet manual and the right on the loud one and you’ve got a nice solo going. Separation of sounds is a huge advantage of the organ. Organs usually have two manuals, however three, four, or even five manuals are not uncommon (some even have more!). Some organs, especially ancient and very small organs, even have one manual.

What are all of the pedals on an organ for?
An organ usually has a pedalboard which gives you one more set of things which you can play with your feet. The pedals usually provide the “bass” of what you are playing. The standard American Guild of Organists (AGO) pedalboard contains 32 pedals and is concave and radiated to make playing easier. Some organs have less, especially historical ancient instruments and home practice instruments. (Home spinet electronic organs of the 50s, 60s, 70s, and 80s often had only 12, sometimes even less pedals). The typical Hammond organ has 25 pedals.
There are also pedals slightly above the pedalboard which look like gas pedals, these are used for opening and closing the chambers to affect the volume. Many organs also have a Crecendo pedal which adds more stops without the organist pulling stops out to create a large sound.

What does “Pulling out all the stops” mean?
Pulling out all the stops means to get the biggest sound you can.
In the real world of organ playing, pulling every single stop actually usually creates a fairly ugly sound on a large organ, but it is certainly very loud.

What are organ pipes made of?
Anything imaginable. A typical organ will have pipes made of a tin and lead alloy, and pipes made of wood. Organs sometimes have other kinds of metal, but lead is often the most preferred since it is flexible and easy to work with. Some ancient instruments have pipes made of early cardboard. One organ in the Philippines is made with bamboo pipes.

Why are locks on organs?
To prevent kids from putting gum under the keys keeping the organ from playing back in the early 1900’s. Stupid kids.
The organ has continued to have a lock on it to prevent vandalism and destruction, as well as to prevent people who “don’t know what they are doing” from trying to use the organ. The advantage is prevented damage, the disadvantage is a lesser number of people having access to the organ.

How long does it take for an organ to start up?
Usually not very long. For example, a three rank church organ I frequently play takes about 10 seconds. A 10 rank theater organ I play takes about 10 seconds before it reaches the pressure necessary to play, and a 15 rank baroque tracker I frequently play takes about the same amount of time.
An organ should be left on at least an hour before a concert and before tuning to help the instrument get to the temperature it needs to play at a good pitch since pitch is directly affected by the temperature of the room, air, and pipes.

An electric Hammond organ takes about 30-45 seconds to startup because you must start the starter motor, the running motor, and then shut the starter off, and wait for the tubes to warm up. Other analogue organs that use tube technology take a similar amount of time.

Are tracker organs harder to play?
Yes, in some respects. Tracker organs use a mechanical connection between the keys and the actual organ. This makes the keys harder to press, especially if you use couplers. Some tracker organs are better than others.

People often speculate that the reason less women have historically played organ is because of the literal amount of strength it took to play some much older organs.

Why are tracker organ still popular?

Many organists believe that a tracker action gives more direct control of the organ. This is kind of true. Striking a key faster causes a slight variation of the initial sound of the pipe.
Tracker organs use ventil chests which have a slight delay in the full air pressure to the pipes, causing a “chiff”. This is an often desired sound.
Mechanical tracker actions are less prone to failure.
Many tracker organs can be run without electricity (with the assistance of a person to keep the bellows full).

Where is the largest organ in the world?
In a Macy’s store in Philadelphia. It is most frequently called the Wanamaker Organ (after the company that built it).

What pitch are organs at?
Modern organs typically are at the standard A440. Some theater organs of the 1920s are at around 438. Older organs may vary greatly. Baroque organs have a different tuning temperament which is far too complicated to explain here. The organ can be completely re-tuned to a different pitch, however the amount of movement available is limited and this takes a while to do.

How many pipes does an organ have?
Anywhere from as many keys are on the organ to a few thousand. A 3 rank MP Moller than I frequently play has a bit more than 200 pipes in it. The Wanamaker Organ, the worlds largest playing organ at a Macy’s store in Philadelphia, is estimated to have about 28,543 pipes.