HARMONIUM The harmonium is a keyboard instrument. Thin metal tongues vibrate to a steady current of air produced by pumping the bellows. The harmonium has a three-octave keyboard. This compact organ was introduced in the early 19th century by European missionaries to sing hymns in remote villages, where it was impossible to carry a heavy church organ. Later, it became a part of the music of the subcontinent. The harmonium in its present form has completely vanished from the musical scene in the western countries of its origin. In Pakistan, the harmonium is very popular as an accompaniment to solo singing and Qawwali singing.