Instrument
Organ (Pipe Organ)
A keyboard instrument that pushes air through pipes instead of striking strings.
The pipe organ is played from a keyboard (often several, called manuals, plus a keyboard for the feet called a pedalboard), but produces sound completely differently from the piano: pressing a key opens a valve that lets air flow through one or more pipes, each pipe built to sound a specific pitch and tone color. A large organ can have thousands of individual pipes, organized into "ranks" or "stops" that the player selects to shape the instrument's tone.
That mechanism lets a single organist control an enormous range of tone color and volume — from a single whisper-quiet pipe to the full combined weight of every rank sounding together — making the organ one of the loudest and most texturally varied instruments in existence. Its history is tied closely to the church, where large pipe organs have been installed for centuries specifically because they can fill vast stone buildings with sound, and much of the core organ repertoire (including Bach's organ works) was written for exactly that setting.
Where to start listening: Bach's Toccata and Fugue in D minor is the instrument's single most widely recognized piece.