Pipe organs in Themiclesia
Pipe organs in Themiclesia are often installed in civic, religious, and artistic spaces where music is needed. There are more than 2,000 pipe organs in Themiclesia, the majority whereof are located in churches. Organs were introduced to Themiclesia in the late 14th century and evolved under both foreign and domestic influence, foremost from the Ostlandic and Sieuxerrian traditions, and since the 18th century Themiclesian organ-building was often done under a domestic, synthetic tradition of tonal design. Organs function as solo instruments and as an ensemble instrument in the modern Themiclesian orchestra.
History
Tonal design
Divisions
The basic plan for an instrument in Themiclesian tradition is outlined by the number of divisions or bri (徘), which could be a "flue" division (管徘) or "instrument" division (樂徘). A flute division is dominated by the pipe organ's natural sound or principal chorus, while an instrument division serves to imitate a range of musical instruments. A division usually corresponds to a manual on the organ console, save for floating divisions which could be coupled to one or more manuals, and the manuals are typically in this order from the lowest:
- Principal, containing the most powerful principal chorus.
- Positive, containing a secondary principal chorus and in its own, smaller case located behind the console.
- Récit, containing mainly imitative stops and under expression; this is usually dominated by string and flute stops.
- If a fourth manual is present, it could be:
- Echo, containing softer imitative stops and enclosed, typically located behind the console so as to produce an occluded voice;
- Over-positive, similar to an echo division but unenclosed.
- If a fifth manual is present, its position not necessarily at the top of the console, it could be:
- Hind-Positive, containing a third principal chorus, between the principal and positive in prominence;
- Under-positive, similar to Echo but located under the main organ if located on an organ loft;
- Solo, containing high-pressure reeds.
Aside from the number of divisions, the size of the instrument is also conveyed in terms of its longest (i.e. lowest) rank in the principal division. Most two-manual organs are 8-foot instruments, while large instruments often have 16-foot tone in the principal division. There are five organs in Themiclesia known to be 32-foot instruments, which have 32-foot tone in the principal division.
The terminology of "onefold" through "sixfold" organs technically refers to the number of chests of mixtures that span the front of the organ case, where a "twofold" instrument has two ranks or chests, and so on; the depth of the case is usually limited to two chests, and the size of each chest is restricted by the feasible number of palettes that could be opened by a tracker. Owing to the fixed way in which Themiclesian organ-buildings since the late 17th century have added mixtures, the number of chests provides a loose indication of the size of the division.
The Pedal division in a Themiclesian organ has a complex history, and some older organs preserve an older design for the pedal division. It is usually thought that the early pedal either had no independent stops, merely pulling down on the manual compass, or controlled only a set of stopped flues known as bordonen. Up to about 1800, the pedal division typically had no stop action, and where multiple ranks were available, they typically played parallel octaves and never fifths (16′-8′ or 32′-16′-8′). This design suited the playing of the accompaniment or cantus firmus, because the duller but purer tone of stopped flues allowed the singing voices to dominate. 4′ and 2′ stops did not exist on early pedal divisions because they would cloud the singing pitches.
A more modern pedal division became common around 1750, organized in much the same way as a non-imitative manual division with bass imitative stops inserted to support similar treble voices where present.