The most common reed organ found in North America will be the suction reed organ. When the player presses on the foot treadle, it operated the bellows that creates a suction. This suction or vacuum is then ‘stored’ in the reservoir (also called an equalizer).

How do pump organ stops work?

The keys operate reeds, so when you press the key, air from the bellows flows up the reed and makes a sound. You can change the sound by using the stops, which are pull knobs that add extra features. The expression “pull out all the stops” refers to using all the feathers of an organ at the same time.

Are pump organs still made?

The pump organ ended up being replaced by the electric organ, but it had several decades of popularity. You can still find it being used by certain musicians, but you are not as likely to hear a harmonium in modern times. However, it is still used in Indian music and Pakistani music.