When children learn harmonium, they learn a percussion instrument. The harmonium produces sounds by air when the keys are pressed. The harmonium has its origins in Paris in 1842 and became popular around the world during the late 19th and 20th centuries. The harmonium was initially used in chapels and churches for their choirs. In India, the harmonium is popularly called peti or baja.
A harmonium consists of multiple brass reeds that vibrate when air flows over them, two sets of bellows, stops (main and drones) and a keyboard. Usually harmoniums are made with 1, 2, 3 and occasionally 4 sets of reeds. There are usually two sets of bellows to pump air through the instrument. The "main stops" control how air flows into the reeds. The drone stops, a distinct feature of Indian harmoniums control the flow of air over un-keyed reeds. These drones can be set to any pitch. The most popular pitches are A sharp, C sharp, D sharp, F sharp and G sharp. The keyboard contains 42 black and white keys. Although the keyboard is based on the European style, the drone reeds are typically Indian.
The harmonium was brought into India by the British. Today, it forms an inseparable part of North Indian music. The player uses one hand for the melody and the other for the bellows. In fact, the hand held harmonium was designed keeping the Indian needs in mind. This is because the foot pedals require the player to sit on a chair which is not common in Indian music.
To play the harmonium, a sitting position must be followed. One of these is the standard sitting position. In this position, the harmonium is placed on the ground. A right handed player uses the right hand for the keys and the left hand for pumping the bellows. This is the most preferred position in India. The other position is the qawwali where the harmonium rests partly on the player's lap and partly on the floor.
In some cases, the harmonium is worn around the neck using a strap. In this case, the harmonium can also be played as the player is standing and walking.
A main drawback of the harmonium is that once it is tuned, it cannot be tuned while it is being used.
Some prominent harmonium players in India include Pt. P Madhukar, Pt. R K Bijapure, Pt. Manohar Chimote, Pt. Tulsidas Borkar, Dr. Sudhanshu Kulkarni, Dr. Ravindra Katoti, Ajay Joglekar and Vyasmurthy Katti.