The sarod evolved into a classical instrument about 150 years ago, an expression of the combination of the classical, court-based tradition of the Moghul Empire with instruments derived from the folk-based traditions of Central Asia. The body of the sarod is carved from a single piece of teak covered with a skin head. The steel fingerboard is fretless, permitting the use of the slides, ornaments, and microtones characteristic of Indian music. The brass bell at the end of the instrument acts as a resonator. The sarod has 25 strings, 18 of which are sympathetic. Four main playing strings produce the same note range as a viola. Three rhythm strings are tuned to the tonic note.
The tabla is the classical drum of North India, used to accompany classical vocal or instrumental music since its development in the 18th century. It consists of two small hand drums, the right hand drum is made of rosewood, the larger left hand drum of copper or brass. Both are covered with heads made of multiple layers of goatskin. The black circle of paste and iron filings in the center permits the drum to be tuned precisely to a particular note. The drums, played separately and together, are capable of a wide variety of specific sounds or syllables which are combined into characteristic patterns and compositions.
The tanpura, usually played in the background during a classical concert, provides the tonic drone essential to classical Indian music.