Harmonium /(här*mō"nĭ*ŭm)/

Har·mo·ni·um

Harmonium

n.
  1. A musical instrument, resembling a small organ and especially designed for church music, in which the tones are produced by forcing air by means of a bellows so as to cause the vibration of free metallic reeds. It is now made with one or two keyboards, and has pedals and stops.