The pipe organ is a musical instrument that produces sound by driving pressurised air (called wind) through the organ pipes selected from a keyboard. Because each pipe produces a single pitch, the pipes are provided in sets called ranks, each of which has a common timbre and volume throughout the keyboard compass. Most organs have many ranks of pipes of differing pitch, timbre, and volume that the player can employ singly or in combination through the use of controls called stops.
A pipe organ has one or more keyboards (called manuals) played by the hands, and a pedal clavier played by the feet; each keyboard controls its own division, or group of stops. The keyboard(s), pedalboard, and stops are housed in the organ's console. The organ's continuous supply of wind allows it to sustain notes for as long as the corresponding keys are pressed, unlike the piano and harpsichord whose sound begins to dissipate immediately after a key is depressed. The smallest portable pipe organs may hav