The Harmonium, Pump Organ, Reed organ or melodeon is a type of free-reed organ that generates sound as air flows past a vibrating piece of thin metal in a frame. The piece of metal is called a reed. It is invented in 1842 by Alexandre Debain.
By the second half of the 19th century the harmonium had evolved in to a sophisticated instument. Although the harmonium was a popular instrument in the late 19th century, changes in musical taste led to its early decline in the 1900's.
Some composers who wrote music for a harmonium : Camille Saint-Saens, Cesar Franck, Georges Bizet, Leos Janacek and Max Reger, Jean Sibelius, Arnold Schönberg, Gustav Mahler and Antonin Dvorak.
The best known piece of music is from the Italian opera composer Gioacchino Rossini who wrote Petite Messe Solennelle for chorus, four vocal soloists, two piano's and harmonium.
by René Couty who studied with Alexandre and later with Mustel.