What is an esraj?

The esraj is a bowed lute with frets and sympathetic strings. Museum examples carry four bowed main strings and 15 sympathetic strings, with brass frets tied to the neck. A goatskin soundtable covers the waisted wooden body, and a bone, ivory or horn bridge sits on a strap over the skin. It has no standard tuning; Ma, Sa, Pa, Sa and Ma, Sa, Pa, Pa are two arrangements for the four main strings, as on the closely related dilruba.