Sanxian

From Wiki China org cn

The sanxian (三弦) is a common three-stringed plucked instrument of the Han, Mongolian and other minority ethnic groups. The sound-body is made of round wooden box covered with snake skin, just like erhu. The small sanxian is mostly used for accompaniment in Kunqu opera; while the large one as accompaniment for the northern quyi (Chinese folk art forms, including ballad singing, story-telling, comic dialogues, and clapper talks), dagu (versified story sung to the accompaniment of a small drum and other instruments), and danxian (story-telling by singing to musical accompaniment). Due to its unique tone color, it was later made a part of traditional orchestras.