In Persian everyday usage, radif means row, order and series. However in Persian classical music the word denotes a certain arraying of tunes exerting a special priority, a kind of logic and esthetics declaring a cultivated vision towards music. Radif is used in a least 2 different and simultaneously interrelated meanings in technical music terminology: (1) as an abstract term it signifies the total tunes in all of seven dastgahs in Persian classical music; (2) using n relation with a certain dastgah it means the ordering of existing tunes of that dastgah.
Dastgah in Persian language means "system", as well as "equipment". The suffix "-gah" signifies the place of doing something. For instance daneshgah (university) means the place of science (danesh). Again here dastgah is used in 2 different significations: (1) the total tunes of a certain musical system, e.g. dastgah-e Shur consists of Shur, Abuata, Bayat-e Tork, Afshari, Dashti and their related gushehs; (2) the frets of a string instrument (dast means "hand", hence dastgah denotes "the place of hand").
The Persian classical music consists of seven major systems (dastgah) and five minor ones (avaz). Thus we can say that radif is the totality made by these 7 dastgahs and 5 avazes. ...