The erhu can be dated back to the Tang dynasty (618-907) and is said to have developed from the earlier Mongolian xiqin. It belongs to the huqin family that also includes the zhonghu, sihu and gaohu. Initially used as accompaniment in opera, the erhu later acquired the role of solo instrument. It is also used in small ensembles and large orchestra. Besides classical music, the erhu is also frequently heard in modern Mandarin popular music.

The erhu has two strings, but there are no frets (as on a guitar)

and unlike the violin there is also no touching board. Instead of pressing down on the strings, the player will simply touch the strings to produce the appropriate pitch.

The sound body of the erhu is a six-sided case often covered in snakeskin. The erhu is played in an upright position, with the case in the players lap. The erhu is played using a horsehair bow, but unlike the violin, the hair run between the strings of the erhu and the bow cannot be removed from the instrument.