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.

Tonal design

The basic plan for an instrument in Themiclesian tradition is outlined by the number of divisions or bri (徘), which could be a "flute" 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 corresponds to a manual on the organ console, except for floating divisions, and the manuals are typically in this order:

1. Principal, containing the most prominent principal chorus
2. Positive, containing a secondary principal chorus and in its own, smaller case located behind the console
3. Récit, containing mainly "instruments" or imitative stops and enclosed
4. If a fourth manual is present, it could be:
   • Echo, containing softer imitative stops and enclosed, typically on top of the organ case
   • Oberwerk, similar to an echo division but unenclosed
5. If a fifth manual is present, its position not necessarily at the top, it could be:
   • Hind-Positive, containing a third principal chorus, based on 16-foot voice and between the principal and positive in prominence, present in select, very large instruments where the principal division contains a 32-foot principal voice
   • Antiphonal, similar to Echo but located some distance away from the main organ and could be enclosed or unenclosed
   • 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 a 16-foot voice in the principal division. There are six organs in Themiclesia known to be 32-foot instruments, which have a full-length 32-foot stop 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.