The sanxian is a Chinese lute — a three-stringed fretlessplucked musical instrument. It has a long fingerboard, and the body is traditionally made from snake skin stretched over a rounded rectangular resonator. It is made in several sizes for different purposes and in the late 20th century a four-stringed version was also developed. The northern sanxian is generally larger, at about 122 cm in length, while southern versions of the instrument are usually about 95 cm in length.
The sanxian has a dry, somewhat percussive tone and loud volume similar to the banjo. The larger sizes have a range of three octaves. It is primarily used as an accompanying instrument, as well as in ensembles andorchestras of traditional Chinese instruments, though solo pieces and concertos also exist. The sanxian is used in nanguan and Jiangnan sizhu ensembles, as well as many other folk and classical ensembles.
Traditionally the instrument is plucked with a thin, hard plectrum made from animal horn but today most players use a plastic plectrum (similar to a guitar pick) or, alternatively, their fingernails. This use of fingers to pluck the instrument often shares technique with that of the pipa and is most commonly used in performance of sanxian arrangements of works traditionally written for the pipa. This allows for pipatechniques such as tremolo to be used. Other techniques for sanxian include the use of harmonics and hitting the skin of the instrument with the plectra or fingernail .
Although the sanxian has historically been one of the most popular Chinese folk instruments (particularly for accompanying singing), a major decline in the number of sanxian players in classical contexts has been the cause of great concern among enthusiasts of the instrument. As many Chinese orchestras exclude the sanxian, many people are unwilling to learn this instrument. Even in China, very few conservatories offer majors in sanxian, and the small number of students of this instrument, as compared to the guzheng or pipa, for example, have led to further concerns that the instrument's rich playing traditions may be lost forever. One reason for this is the fact that, unlike the shamisen in Japan, the sanxian lacks an original solo repertoire of its own, with most sanxian solo pieces being arrangements of pipa melodies, as in the case of "Big Waves Wash Against the Sands". For the most part, use of the sanxian in the Chinese orchestra is as a provider of a de facto bass line. Also, as the neck of the da sanxian is particularly long, there is a great deal of limitation on how virtuosic a sanxian player can be. This is not an issue in the smaller saxian, which are closer in size to the Japanese shamisen.