A Chinese bowed string instrument similar to a violin with two strings. Although it dates back to the Song Dynasty in about 1100 AD, its use as a solo instrument has only been since around the early 20th century. The instrument measures around three feet long with a long neck and a relatively small soundbox three or four inches in diameter and five to six inches deep available in several shapes (round, hexagonal, or octagonal). The scroll is often decorated with a carving of a dragon's head or a crescent moon and the soundbox is often decorated. The Er Hu also will use a metal clamp or silk string clamp that acts as a capo to change the open pitches of the strings. The bow is made of bamboo. The sound of the Er hu is similar to a violin but much thinner in its timbre.