Setar (Persian: سه تار, from seh, meaning "three" an tār, meaning "string") is an Iranian musical instrument. It is a member of the lute family. Two and a half centuries ago, a fourth string was added to the setar, which has 25 - 27 moveable frets. It originated in Persia around the time of the spread of Islam and is a direct descendant of the larger and louder tanbur. The setar is significantly different from the Indian sitar, with which it is sometimes confused due to the similarity of their names.