This small instrument is the Persian version of the saz, having a variety of body constructions, but all have the long tied-fretted neck and 4 strings in three courses. Setar means 3-string; the higher octave was added to the lowest string by the Sufi Moshtaq Ali Shah last century. The instrument is a favorite among both mystics and Persian classical theorists. A soft instrument, it was usually played alone, although there is a new custom of playing in setar ensembles that is growing in popularity. The full name for this instrument is chahartar, or 4-string, but today it is a 6-stringed lute set up in 3 paired courses, the lowest having a high octave double. This is one of the instrument in this book with a skin resonator, in the form of two skins on an hourglass shaped carved wooden body. the larger skin is farthest from the neck and the bridge rests on this section. The neck has a large peg box with big turned wood pegs, tied frets, and often a light wood or bone strip inlaid the length of the neck. Fine instruments are well carved but sparsely decorated, and can fetch astronomical prices for a Yayeh or Sharoch instrument.

Jeff Martin plays the tar for the Alhambra version of the River accompanied by Stuart Chatwood on the Santoor. Jeff Martin has been known to say that it "looks like a peanut on a stick".