Thampura (Tamboura/Tambura) is a long-necked, fretless lute that supplies a drone accompaniment in Indian music. Resembling the tanbur, the Middle Eastern lute from which it derives its name, usually has four metal strings tuned (relative pitch) c-c'-c'-g or c-c'-c'-f. Precision tuning is achieved by inserting bits of wool or silk between the strings and lower bridge and by adjusting small beads attached to the strings. It is the most prominent drone instrument in Carnatic Music. It accompanies the voice and all melody instruments except the Nagaswaram. With Nagaswaram the Ottu, a longer version of the Nagaswaram but without finger holes is used as an accompaniment.