Some theoretical notions before tuning your Setar (or Tar):
Persian classical music like many other Oriental classical musics does not consider as compulsory the use of Western music standardized pitch or the commonly called A440 ("A = 440 Hz"). This Standardization was established in 1939, and was mostly designed to cut through tuning problems in European music orchestration (which can use up to hundreds of instruments and choir). It means that in an orchestra all instruments and vocals have to conform to that standard.
Such a problem (e.g. huge orchestras) obviously doesn't exist in Iranian music as ensembles historically have had a limited number of musician and singers. Moreover, in Persian music primacy goes to human natural voice and not a mechanical sound. This means that if there is a vocalist in the ensemble (male or female), the instrumentalists have to tune according to his or her voice. Tuning according to the vocalist’s voice requires rather advanced knowledge of both the instrument and vocal performance.
Now, if there is no vocalist, Persian music can be very flexible and the tuning pitch of strings can in theory be anything :
Comparing the « Persian music C / Do » (pmC) and the « Western music C / Do » (wmC) the result could be : pmC=wmB ; pmC=wmA# ; pmC=wmA etc. including the match of Western standard with pmC=wmC.
In other words, if a Persian classical music perfomer says « I’m tuning my Setar to ‘C G C C / Do Sol Do Do’ to play a melody in Dastgah e Mahoor » his/her C could be A, A#, B, C… for a Western classical music performer.
In reality, there are some established practices : the most commonly used tune is « pmC = wmA# » .
So one might ask why not to conform to Western standards, in the absence of a vocalist, or why most great masters never tune to Western standard C. The reason has nothing to do with nationalism but with some practical considerations. When you tune your Setar slightly lower than the Western pitch, Setar simply sounds better. It is a matter of experience ! For instance Ostad Hormozi used to tune to rather low pitches pmC=wmA (see), while Ostad Saba mostly used pmC=wmA# (listen).
Notice about frets: As Setar or Tar's frets are made of guts, they are ajustable and have a limited life span depending on the frequency of playing the instrument. So every time you change them be sure that they are in the right position and perfectly tuned. That is why we prepared this online tuner so that you can adjust them all.
When tuning, let the sound player of each note turn in loop, so you can get closer and closer to the right note.
The first step is to have the right tune for the four strings (or three double strings for the Tar). Be careful of turning the tuning keys (Gushee in Persian) slowly. The strings may break if you go too fast and too high.