Har-mo′ni-um.
（Music.) A musical instrument whose tones are produced by the vibration of metallic reeds operated by keys. The bellows are worked by pedals, and the keys are arranged in one or two b inks. These instruments are made with a variety of stops, and with swell and tremolo attachments. The instrument is used as an organ of small size in parlors, and in churches in the performance of sacred music. The melodeon and parlor-organ are of this class. The harmonium is substantially the same as the seraphine introduced by Green, and has been blessed with a variety of names derived from the Greek and other sources. Among them are oeolophon, oeolomusicon, physharmonica, melodeon, symphonium, and poikiorguc. The free tongues of the harmonium, though used from time immemorial by the Chinese, were introduced into Europe by M. Grenie in 1810.
