flow through. A large stop simply means that the pipes are longer, the actual stops themselves are the same size. The blower is a pump that blows air through the pipes specified by the notes played and the stops used. Different sets of pipes have different sounds and volume which are governed by the length and shape. They can be flutes or reeds. In flutes, the sound is produced from air flowing past an opening, whereas in reeds, it’s created by a vibrating piece of brass. The length of the pipes controls the octave of the notes. They can be 2, 4, 8, 16, 32 and even 64 feet in length (0.6, 1.2, 2.4, 4.8, 9.6 or 19.2 meters). Some stops cause air to flow through a mixture of pipes and are therefore called ‘mixtures’. A combination of these give the organ it’s unique yet instantly recognizable tone. The tone will be chosen by the organist by selecting appropriate stops and varies from piece to piece, often changing during a piece. It is not hard to imagine how much space such an instrument will take, the biggest of which is shown occupying 310(W)x137(H)x456(L) feet. This begs the question: where does it all go? The answer, however, is not what one would expect. Some Chapels, churches, etc, have the luxury of space and simply have massive sets of pipes that are 64 feet in height, the longest in the world.
at Atlantic City; the other is a Contra Trombone at the Sydney Town Hall. Therefore the answer to the question above is simply: it doesn’t. This is where the element of acoustics plays its best card, the illusion of deeper sound. When two pure tones (a sound with a sinusoidal waveform) are played, they combine to create two more sounds, with frequencies which are the sum and difference of the first two. This means that stops that are much smaller can be used to produce lower frequency tones that usually require a bigger set of pipes. This bass is called resultant bass and the new organ in Radley will have a stop with a resultant 32 feet bass though it is “only” 16 feet in length. This occurs at all frequencies but is most prominent at the lower, bass register.
So to summarize, the organ is the largest instrument in the world and is very old. It has been used in a variety of different locations across the world and can create a vast variety of tones and sounds that are distinct and instantly recognizable. However, there is a decline in the number of organists as there is a decline in the number of functioning organs, due to the cost, size and maintenance of the organ. As an example, during warden’s music every year you see how long it takes for the orchestra to tune using one note. Now imagine tuning There are only two true 64 foot stops in every single note on every single instrument existence. One is the Diaphone Profundo one at a time!
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