Bowed string fiddles have existed in China since the Tang Dynasty; their predecessors were likely fiddles introduced from Persia through cultural trade along the silk road. For much of its history, the èrxián and associated fiddles were viewed as folk instruments of southern China and only in the 20th century have they become a national art form.
The èrxián is under the sīzhú 絲 (“silk”) classification of instruments, owing to the traditionally silk strings which produce the sound. This classification, called bā yīn 八音 (“eight sound”), is a system whereby instruments are grouped by their material and was first used during the Western Zhou Dynasty. The eight sounds being: bamboo (composed mainly of woodwinds), wood (percussion), stone (chimes), metal (bells), clay, gourd, skin (drums), and of course, silk.
The èrxián is played by placing the base on the left leg, with the left hand fingering the notes, and the right hand holding the bow in an underhand position. The bow hair is slotted in between the two strings and rests on the soundbox while being played. The tone of the èrxián, èrhú, and other bowed instruments in the húqin family is very distinctive, and often described as melancholy, with a nasal pitch.
The major components of the èrxián include the soundbox, the neck, the strings and pegs, and the bow. The soundbox—which is also referred to as the resonator—can be cylindrical, hexagonal, or rectangular. Its front face is covered in a snakeskin, most commonly a python skin because of its flexibility. Situated on the face of the soundbox is a wooden bridge and cloth dampener. It is an unfretted instrument, i.e. no finger board. The nut—or qiān jīn 千斤—is usually a piece of string or metal wire which holds the strings a certain distance from the neck. The inner string (closest to the player) is tied counterclockwise to the top peg, and the outer string is tied clockwise to the lower peg. The bow is most commonly made of horsehair and bamboo, the two strings traditionally were twisted silk, but modern alternatives include nylon or metal.