Organ console

The pipe organ is played from an area called the console or keydesk, which holds the manuals (keyboards), pedals, and stop controls.

On modern organs, the registration can be changed instantaneously with the aid of a combination action, usually featuring pistons.

Pistons are buttons that can be pressed by the organist to change registrations; they are generally found between the manuals or above the pedalboard.

[1] Newer organs in the 2000s may have multiple levels of solid-state memory, allowing each piston to be programmed more than once.

In a horizontal row of stop tabs, a similar arrangement would be applied left to right rather than bottom to top.

(The name "Choir" is a corruption of "Chair",[1] as this division initially came from the practice of placing a smaller, self-contained, organ at the rear of the organist's bench.

[2] Some larger organs contain an Echo or Antiphonal division, usually controlled by a manual placed above the Solo.

On French instruments, the main manual (the Grand Orgue) is at the bottom, with the Positif and the Récit above it.

[citation needed] In addition to names, the manuals may be numbered with Roman numerals, starting from the bottom.

Many new chamber organs and harpsichords today feature transposing keyboards, which can slide up or down one or more semitones.

Modern organs are typically tuned in equal temperament, in which every semitone is 100 cents wide.

Many organs that are built today following historical models are still tuned to historically-appropriate temperaments.

[citation needed] The range (compass) of the keyboards on an organ has varied widely between different time periods and different nationalities.

Enclosure is the term for the device that allows volume control (crescendo and diminuendo) for a manual without the addition or subtraction of stops.

[2] All the pipes for the division are surrounded by a box-like structure (often simply called the swell box).

The most common form of controlling the level of sound released from the enclosed box is by the use of a balanced expression pedal.

Many ratchet swell devices were replaced by the more advanced balanced pedal because it allows the enclosure to be left at any point, without having to keep a foot on the lever.

[4] A device called a coupler allows the pipes of one division to be played simultaneously from an alternative manual.

Some organs feature extended ranks to accommodate the top and bottom octaves when the super- and sub-couplers are engaged (see the discussion under "Unification and extension").

The system as found in Truro Cathedral operates like this: This allows four different sounds to be played at once (without thumbing down across manuals), for example: