|About The Organ|
The organ is the oldest keyboard instrument and has the honour of possibly being one of the most complex musical instruments ever to be constructed. Though varied in size, it is most frequently imagined in all its full-sized glory. It is probably a combination of its qualities of size, appearance, sound and versatility that has caused the organ to be known as the king of instruments.
An instrument recognisable as organ-like was known to have existed as far back as the third century BC but before continuing it is perhaps appropriate to identify the characteristics needed to be considered " organ-like."
Firstly, it must be accepted that an instrument of such complex magnitude is, basically, nothing more than a set of differently pitched whistles. To acknowledge this fact identifies the first two of the four characteristics of an organ; namely, pipes and a supply of wind. The third characteristic is that there needs to be a method of directing the wind to chosen pipes and fourthly, a means of releasing the wind into the appropriate pipes.
By considering these criteria we can judge whether the invention of Ctesibius of Alexandria was organ-like. His invention was called the hydraulis and, as its name suggests, water was involved in its operation.
The task attempted by this early Greek inventor was to play the pipes without the need for blowing: that is, he wanted mechanical panpipes.
Ctesibius addressed this problem by designing a reservoir for air. Initially, this reservoir was filled with pressurised air by means of a bellows system. An integral part of the sealed reservoir was a series of valves that were operated by keyed levers. The appropriate number of valves was situated adjacent to the bottom of corresponding number of pipes so that, upon the activation of a selected key, pressurised air passed into the pipe thus producing a note of the desired pitch. Constant air-pressure was ensured by using a cone-shaped device with the open funnel-end immersed in a large container of water. The narrow end of the funnel-shaped skin was secured into the reservoir of air.
As air was expended through key activation, equalising replacement pressure forced the cistern-stored water up into the funnel maintaining the constant pressure in the reservoir. (One presumes that at some point the bellows operatives would have to top up the reservoir of air.)
So Ctesibius' hydraulis was, indeed, organ-like. It had pipes, a wind supply, a method of aligning the wind supply to the pipes and a keyboard to initiate air movement.
Citizens of the Byzantine and Roman empires were known to have enjoyed music performed on multi-piped instruments similar to the hydraulis but gradually bellows were becoming the preferred method of supplying a constant stream of wind.
These bellows-type instruments migrated into eighth and ninth century Europe through contact with the Arabic descendants of members of the Byzantine eastern Roman empire.
By around 950AD there are accounts of a wondrous organ in Winchester Cathedral, England. It was said to have four hundred pipes and twenty-six pairs of bellows, the operation of which required seventy men. Three people were said to operate the two manuals by manipulating sets of heavy, wooden sliders. Even if this account is the exaggeration of someone overcome with wonder at such a magnificent instrument, the reality must still have been extremely impressive.
A "great" church organ was built in 1361 at Halberstadt in Germany. It had three manuals, a pedal-keyboard (a very early reference) and ten men were needed to work its twenty sets of bellows.
During the Middle Ages, three organs emerged. As at Halberstadt, the huge descendants of the Winchester organ were still required in the large Gothic cathedrals of that time but within churches the smaller positive organ was sufficient. Even smaller was the portative organ that, as its name suggests, was transportable. This portable organ was carried, strapped to the player who pumped with one hand and played with the other. The portative organ was used in processions but it was also associated with secular music and it would have been used to accompany dance and other itinerant festivities. The positive and great organs required someone other than the organist to operate the bellows.
By the fifteenth century, organs were very similar to modern organs so having arrived at this point in the history of this very complex instrument it might be the proper time to investigate its workings.
The level of mathematical, technological, mechanical, scientific and practical skill required to construct an organ is truly amazing and it is with trepidation that one attempts to describe such a feat.
Pipes, arranged in rows known as ranks, were of varied length, shape and material: variables that influenced the pitch and tone of the pipes so that each rank had its own characteristic range and quality.
Pipes were of two types:
The length of the pipe determined the pitch and an eight-foot length produced the basic pitch of the organ. By extension, a four-foot length would sound an octave higher and a sixteen-foot pipe would sound and octave lower. It is quite usual for organs to have a sixteen-foot pipe, less frequent to have a thirty-two foot pipe and rare to have a sixty-four foot pipe. Smaller pipes descend into dimensions as small as inches so the compass of the largest organs can be as much as nine octaves.
Smaller organs avoided the necessity for pipes of extreme length by adopting the practice of blocking (stopping) the open, upper end of a pipe. The resultant effect was that an eight-foot pipe could replicate the pitch of a sixteen-foot pipe. Stopping also influenced the tone quality.
So, there we have several ranks of pipes of various type, shape, length and material awaiting the delivery of sufficient wind to make them sound.
From whence is this wind to come? From a hand or foot-pumped, bellows-fed reservoir known as the windchest. This windchest had in its top rows of holes aligned and sufficient to complement the ranks of pipes congregated above.
To match the holes to their corresponding pipes is easy yet pointless since the bellows-pumped wind would immediately dissipate simultaneously through all the pipes. A system whereby the wind is restrained, controlled and directed has to be introduced.
The linear arrangement of the ranks helps overcome this challenge. A long, straight, thin piece of wood with holes punched accurately to align exactly with the ends of the pipes in the specified rank is introduced with the facility for a forward and backward sliding motion. This piece of wood is known as the slider. When it is slid forward in its default setting, the holes are not aligned with the pipes so that every pipe in that rank is stopped and dormant. Pull out the slider and the holes and pipe-ends become aligned and capable of allowing wind to pass into the pipes. (The pedal usually engaged the ranks of the deepest pipes.)
This system of sliders evolved into the characteristic arrangement of knobs that are pulled and pushed by the organist as she or he brings selected ranks into and out of action. Because an effect of manipulating the sliders is to stop a rank, the term "stop" refers to the rows of knobs on the console and, by association and usage, it also refers to the pipes themselves.
We are now at the point where one, two, three or more ranks, in any combination, can be active or passive according to the organist's operation of the sliders by means of the stops. This simple yet efficient mechanism is still not sufficient because it can only influence complete ranks; pushed in, all pipes in the rank are redundant; pulled out, all pipes in the rank are active. There needs to be a method for discriminating between individual pipes within a rank.
We now address the action of the organ. "Action" as in the action of a pianoforte: an integral mechanism that produces sound as a result of various inter-related movements initiated by a keyboard.
When a key is depressed it initiates a series of linked movements that result in the opening and closing of a hinged lid set at the working end of a pipe. The hinged lid is known as the pallet and the arrangement of rods and levers connecting it to the keyboard consists of trackers and stickers. Also included within the connective sequence is a gravity-assisted backfall element.
The end result of all this ingenuity is that when an organist presses a key she or he is rewarded with the tweet, toot, peep or permp that they selected.
This has been a simplification of the construction and workings of an organ. The precision and craftsmanship involved and the complexity of the workings extend way beyond what a brief description can communicate. For instance, the mouth of every pipe is individually shaped by bending, shaving and cutting until the resultant pitch and tone quality blends exactly to create each organ's unique sound. Similarly such are the number of stops and keys needed to service perhaps eighty ranks containing four thousand pipes that one manual is insufficient to accommodate all the possibilities of tone, timbre and effect.
The organist sits at a console with as many as five manuals, each of which could be an organ in its own right. These manuals have such individual qualities that they are actually named as separate organs. The Great Organ is the premier manual. The Swell Organ is so named because of its ability to swell and diminish as pedal-operated doors open and close around the designated pipes. The other manuals are the Choir Organ, the Solo Organ and the Echo Organ. (Not all organists are faced by such an array. Three is a usual complement of manuals but one and two can suffice.)
In addition to all the stops, keys and manuals the organist can have as many as thirty-two pedals at her or his disposal. (Pedals, incidentally, were introduced in Germany as early as the late fourteenth century but the rest of Europe lagged so far behind that the pedal was not common in England until the first half of the nineteenth century.)
Due to beautifully decorated and illustrated manuscripts it is deduced that plainsong would occasionally be accompanied by instruments. There are representations of bagpipes, hurdy gurdies, reed pipes and drums but these were the instruments of the profane, secular world. It is certain that the demands of accompanying plainsong were within the capabilities of the organ and thus its association with church music began.
The first music written for the organ was secular and it appeared in the fourteenth century. The courtly songs and dances of that time were accompanied by fiddles, lutes and psalteries but introduced to that ensemble was the small organ.
The solo repertoire of the organ, sacred and secular, increased during the sixteenth and seventeenth century but it was with the arrival of JS Bach (1685-1750) that organ reached its never-to-be equalled peak.
Even though composers of the quality of Handel wrote concerti for organ, that form has never proved very popular. The organ remains proudly a solo instrument.
The appearance of controlled electricity in the late nineteenth and twentieth centuries have had a great influence upon the actual workings and sound production of organs.