A tamboura (or tanpura) is the instrument that you hear in the background of most Indian music. There are different sizes of tambouras that have different pitches. Some of them are very large, usually used for kirtan chanting. There are also smaller models that are used for accompanying solosts or other instruments.
Most tambouras have a body made from a gourd and a neck made of wood. Other tamboura models are constructed completely from wood, making them easier to transport but not as resonant.
The tamboura does not play the melody of the music but has a unique role. It provides a dynamic harmonic resonance, rich with overtones, that is based on the basic note of the musical piece.
It is not difficult to learn to play a tamboura, but it takes a steady hand and a focused mind to properly accompany on a tamboura. Learning to play can be a peace-evoking, mind-calming endeavor.