Dastgah

Dastgāh (Persian: ‎‎) is a musical modal system in traditional Persian 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 that a performer uses as the basis of an improvised piece.

Each dastgāh consists of seven basic notes, plus several variable notes used for ornamentation and modulation. Each dastgāh is a certain modal variety subject to a course of development (sayr) that is determined by the pre-established order of sequences, and revolves around 365 central nuclear melodies known as gushehs (each of these melodies being a gusheh), which musicians come to know through experience and absorption. This process of centonization is personal, and it is a tradition of great subtlety and depth. The full collection of gushehs in all dastgāhs is referred to as the radif. During the meeting of The Inter-governmental Committee for the Safeguarding of the Intangible Heritage of the United Nations, held between 28 September – 2 October 2009 in Abu Dhabi, radifs were officially registered on the UNESCO List of the Intangible Cultural Heritage of Humanity.

The dastgāh system has been a major influence in the maqam system in the Arabic music, both of which are deeply rooted in the Sassanid Persia's melodies, which entered into the Islamic world following the Arab conquest of Iran in the 7th century.

The system of twelve dastgāhs and gushehs has remained nearly the same as it was codified by the music masters of the nineteenth century, in particular Mîrzā Abdollāh Farāhāni (1843–1918). No new dastgāh or large gusheh has been devised since that codification. When in the modern times an āvāz or dastgāh has been developed, it has almost always been through borrowings from the extant dastgāhs and gushehs, rather than through unqualified invention. From this remarkable stability one may infer that the system must have achieved "canonical" status in Iran.

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