The Radif

Radif (Persian: ردیف, meaning order in Persian) is a collection of many old melodic figures preserved through many generations by oral tradition. It organizes the melodies in a number of different tonal spaces called Dastgah. The traditional music of Iran is based on the Radif, which is a collection of old melodies that have been handed down by the masters to the students through the generations. Over time, each master's own interpretation has shaped and added new melodies to this collection, which may bear the master's name.
The preservation of these melodies greatly depended on each successive generation's memory and mastery, since the interpretive origin of this music was expressed only through the oral tradition.

To truly learn and absorb the essence of the Radif, many years of repetition and practice are required. A master of the Radif must internalize the Radif so completely to be able to perform any part of it at any given time.

The Radif contains several different dastgahs which are distinguished from each other by their relationship of note intervals and the form of the movement of the melodies within them. A dastgah portrays a specific sonic space. A dastgah may contain approximately from 10 to 30 goushehs (melodies). The principal goushehs of the dastgah specify the different scales within that dastgah. The note, upon which the gousheh is based and often is the center of the gousheh, is called the shahed. The shahed moves when we modulate between principal goushehs, and this movement creates a new sonic space. Rhythm in these melodies takes three different forms: symmetric, asymmetric (lang), and free form. The rhythm is greatly influenced by the rhythm and meter of the Persian poetry. The instrumental and vocal Radif are different from the rhythmical point of view; however, their melodic structures are the same.