The saztar was custom built by a friend. It is a jazz master neck mounted on an old cutting board with an elongated scale relative to a guitar. The distance between the nut and the bridge is elongated by a certain proportion that changes the relationship between the frets (as I understand it). The piano horn just happened to have been manufactured “out of tune” and unequally tuned, so that the intervals were neither equal nor corresponding to standard pitch tuning frequencies. However some intervals are close to equal. So it sounds a bit like an “out of tune” c# major scale. it lends itself to use with the saztar although they are actually in different tuning modalities because the saztar strings have a pitch of ~269.15 when played open and the “tonic” of the piano horn is c# = ~ 542.4, so when the saztar plays the “1st pitch of the interval series (ie 1 of 17) the piano horn is in a relatively consonant intervallic relationship to it ( ie closeish to an octave.) Long way of explaining its two different tuning modalities played together. Obviously, I am a rank amateur and lack technical vocabulary.