Harmonium is a key board instrument was designed by Alexandre Debain from Paris in 1842. It is known as pumped organ also. The technology to produce sound is very simple . here sound is produced by air supplied by the device called bellows being blown through the sets of reeds.. in ancient time ,people witnessed foot operated bellow also . Generally harmoniums are available with 3 or 3and half octave and seven folded bellows. It is easy to play . The most popular manufacturers of the instrument are Sardar & sons and Paul &Co.kolkata.
at present Scale changing facility is also available on harmonium. It is an indespensable instrument for singing Ghazals & Qawali.
Piano : it is also played with keybord but without bellow . the technology differs from Harmonium . Air supply is not important to produce sound. There are many types of piano.the grand piano and the upright piano are the main with subcategories. A modern piano has 36 black keys and 52 white keys for a total