The stop knobs

Each knob corresponds to a rank of pipes (more than one rank for "Mixtures"). When a stop knob is pulled out, the pipes are able to sound. The arrangement of stops selected on the organ is called "registration" and is often marked on music (eg "Flutes 8,4")

The music desk

Where the organist can put their music!

Manuals

Played with the fingers. Each manual controls one division of the organ (except when couplers are used). There are 61 notes (five octaves), with the lowest note two octaves below Middle "C" (on an 8-foot stop)

The Town Hall organ has four manuals, from bottom to top: Choir, Great, Swell and Solo (which also plays the Bombard)

Pedal board

Played with the feet, control the Pedal division (which includes the largest pipes in the organ). There are 32 notes from 3 octaves below Middle "C" to G (on a 16-foot stop).

Couplers

These join the different divisions together - so for example, if the "Swell to Great" coupler is pulled out and the Great manual is played, the Swell organ also sounds.

Swell pedals

Control the swell boxes of enclosed divisions of the organ. From left to right Choir,Swell,Solo.

Pistons

These allow a player to quickly change the settings of many stops at once.

There is a row of thumb-operated pistons under each manual, and also toe pistons above the pedalboard, which are operated by a foot.

Some pistons operate the stops for only one division, some for the whole organ ("generals"), yet others might toggle just one stop, for example a loud trumpet ("reversers")

Sequencer/computer

The pistons and the crescendo pedal are all configurable for each player. A single piston can also 'step through' a sequence of different registrations. Settings can be saved onto or loaded from a USB memory device.

General Cancel

This special piston shuts off all the stops at once - the organist might push this at the end of a performance to ensure that he/she doesn't accidentally make a sound while swivelling around to take a bow!