Answer to Question 1
The rhythm layer is led by the mridangama multi-timbral, double-headed drum tuned to the tonal center of the melodic soloist and is the principal accompanying percussion instrument.
sometimes joined by subordinate percussion instrument(s) such as the ghatam (clay pot), kanjira (Indian tambourine), or), or morsang (jew's or jaw's harp)
Answer to Question 2
The drone, or sruti, layer consists of the sustained (continuously sounding) central tone of the composition and the perfect fifth above the central tone, either played on instruments such as the four-stringed tambura or sruti-box (small reed organ), or provided by small electronic equivalents (synthesizers) that eliminate the need for a performer.