Harmonium is a keyboard instrument and is similar to a reed organ. It is also known as peti or baja. Harmonium is actually a bi-cultural instrument as the keyboard is European but drone reeds come from India.
Various parts of harmonium in brief are as follows: bank of brass reeds, a pumping equipment and a keyboard.
Harmoniums generally consist of one, two, three or sometimes four sets of reeds. When air being blown through sets of free reed, sound is produced. Air is supplied with the help of bellows which can be controlled by hands.
Harmonium is mainly accompanied by a dholak or tabla. It is now very popular in Bollywood music as well as in South Asian religious, folk and classical music.