The esraj and dilruba are extremely similar. The only real differences between the two are that the dilruba has a few more sympathetic strings and a differently shaped body than the esraj.
These instruments are a combination of the sitar and the sarangi. The esraj and dilruba use a neck and frets very much like a sitar, but use a wooden body with a skin head and are played with a bow like a sarangi. The esraj and dilruba are only around 200 years old.
When the esraj is played, one is not supposed to use the frets on the finger board. The frets are simply to let one know where the notes are located. The fingers of the left hand are not pressed behind the frets to play as a sitar or guitar. The fingers press gently onto the string above the fret of the desired note. The player can then slide up and down to create the characteristic sound of Indian music.
The esraj and dilruba can be very squeaky instruments. The traditional bow for these instruments is much heavier than bows for violins and cellos.
The Esraj is found in the east and central areas of India.
The structure of the Esraj has a medium sized Sitar-like neck, with 20 heavy metal frets. This neck holds on a small long wooden rack 12-15 sympathetic strings. The Esraj features 4 main strings which are bowed. All the strings are metal. The soundboard is a stretched piece of goatskin.
You can hear the esraj being played on Samsara.