The harmonium is a keyboard wind instrument in which the sound is produced by metal reeds that vibrate under a stream of air. The air is pumped by the feet through pedal-bellows, so the player simultaneously plays with the hands and “pumps” air with the feet.
The harmonium gained enormous popularity in the 19th century as a more accessible, compact, and cheaper substitute for the organ — for home music-making, small churches, and schools. Its sound is warm, slightly nasal, and sustained, capable of smooth dynamic transitions. Serious composers wrote for the harmonium too. Kindred to it is the hand-pumped Indian harmonium, which became a central instrument of the classical and religious music of India. Today the warm, nostalgic voice of the harmonium is prized in chamber and ethnic music.
