Guitar, Veena-Stringed instruments have taut strings mounted over specially designed wooden frames which are partially hollow from inside where air is trapped in, forms an air column. The air column increases the intensity of musical sound due to the resonance. (Tantu Vadya)
Tabla-All percussion instruments have a taut skin over a hollow metal or wooden frame. When the skin is struck it produces musical sound.(Avanaddhu Vadya).
Shennai, Flute-Wind instruments make use of vibrating columns. In these instruments the air is blown in either directly or through the reeds.(Sushir Vadya)