Playing A Harmonium
Bhava Mini Harmonium
The typical harmonium used in kirtans have two sets of reed, a low octave of bass reeds and a higher set of male reeds. The larger stop knobs are pulled out to activate the main reeds. The smaller knobs (on the right in the knobs picture) each control a single drone reed. These typically correspond to black keys, which are more appropriate for Indian classical music.
Release the latch holding the bellows (either on the top or on the side) and pull out the large stop knobs and gently begin pumping the bellows to get the air flowing (stop squeezing if you feel strong resistance) and press the keys. Keep pumping to maintain a smooth sound and with practice, you'll maintain a smooth, even sound and be able to control the volume by varying the bellows pressure.
Harmonium with Multiple Stops
Some harmoniums have multiple stops for each reed set. On the harmonium pictured below, the first and last knobs control the male reeds while the third and fifth knobs control the bass reeds. There are four drones and seventh knob is a tremolo stop which you don’t want to use!