Dastgah

Dast'gāh (Persian: دستگاه) is a musical modal system in Persian traditional art music. Persian art music consists of twelve principal musical modal systems or dastgāhs; in spite of 50 or more extant dastgāhs, theorists generally refer to a set of twelve principal ones. A dastgāh is a melody type on the basis of which a performer produces extemporised pieces.

Each dastgāh consists of seven basic notes, plus several variable notes used for ornamentation and modulation.