Wikipedia talk:WikiProject PipeOrgan/Sandbox1

Casing


The elements of most organs are housed in a free-standing organ case or a dedicated room called an organ chamber. The free-standing case is considered by most organists and organ builders to be acoustically superior to the chamber because it is said to focus the sound of the organ and project it into the room. The great organ builders of the Renaissance and Baroque periods built organs exclusively in free-standing cases, often with extensive decorative touches such as carved pipe shades, edge mouldings, and even statues.

During the latter portion of the nineteenth century, the shift to chambers began, followed shortly by the shift to electro-pneumatic action. By the mid-twentieth century, some organists (most notably E. Power Biggs) were pleading for a return to the old construction methods (i.e., mechanical action organs in freestanding cases).

In either type of construction, the pipes are separated from the listeners by a grille known as a façade, which often contains decorative pipes. Some organs do not have any discernible pipe façade, or the pipes may be hidden behind a screen. In many organs with façade pipes, especially those based on historical styles from the time before the twentieth century, the façade pipes are connected to the keys and are fully playable. They usually form part of the primary Principal stop from the Pedal or Great division. In other organs, the façade pipes are purely decorative and non-speaking. Whether or not the façade pipes speak, the façade is considered an important part of an organ (much as the scroll of a violin is considered a part of that instrument).

Revision
The pipes, action and wind system of a pipe organ are contained in a organ case. This may be free-standing or built into the architecture. The case is often designed to compliment the design of the building in which it is housed and may contain decorative features such as ornate carvings, statutes and decorative pipework. The pipes that are on display are called the façade, and may be sounding pipes or purely decorative. If they are sounding pipes they are usually comprised of the main Principal or Diapason rank of the organ. The metal may be plain or highly coloured and gilded.

The arrangement of pipes in the façade are in one of three forms: Parallel Movement, Contrary Movement and Pedal Note. Parallel Movement describes pipes in which the tops and mouths move in an inverted V-shape, with the tallest pipe in the middle. These have minimal casework and the pipes hide the action and the windchests. This arrangement is hardly used in the decorative style of French, German and Dutch organ builders where Contrary Movement is preferred. This style, typified by the rising pipe mouths as the pipe tops. Pedal Note describes organs in which the pipe mouths are aligned horizontally giving a clear linear look to the organ.

An organ chamber is a room designed to contain all (or at least one division) of a pipe organ. Because the majority of sound is contained in this room and doesn't reach the auditorium, some of these organs sound muffled and distant. In the 1940s and 1950s, E. Power Biggs was one of a number of organists requesting a return to the free-standing mechanical actions of the Baroque and Classical eras.