It is a stringed instrument akin to the dilruba sounding like sarangi with a sharper but mellower tone. It has frets but is played with a bow and has also sympathetic strings as in sitar. The tonal quality of this stringed instrument is closer to the human voice compared even to the sarangi which is considered to be the best vocal accompaniment with its capacity for elastic modulation and imitating the human voice inflexions. This instrument should be distinguished from dilruba.
Esraj differs from sarangi not only in as much that it has frets but also that instead of gut wires strings are used. It is also somewhat smaller in size than sarangi. Esraj became popular in Bengal and is sometimes called the Bengal variety of sarangi. The wires are tuned Sa-Sa-Pa-Pa. Esraj mainly differs from the dilruba in shape and physical characteristics but is otherwise similar in the technique of playing and popular only in eastern India. It is also used in film music. Some of the notable Esraj players are Vinayaka Bora of Kolkata, Buddhadeo Das, Allauddin Khan and Om Prakash Sharma of Delhi.