harmonium -
A small keyboardinstrument consisting of a series of reed pipes which sound when air is allowed to pass through them by means of a valve that opens when a key is depressed.
Wikipedia
A harmonium is a free-standing keyboard instrument similar to a reed organ. Sound is produced by air, supplied by foot-operated or hand-operated bellows, being blown through sets of free reeds, resulting in a sound similar to that of an accordion.