Wikipedia
Radif (Arabic: رديف) is a rule in Persian, Turkic, and Urdu poetry which states that, in the form of poetry known as a Ghazal, the second line of all the couplets (bayts or Shers) must end with the same word/s. This repeating of common words is the "Radif" of the Ghazal. It is proceeded by a Qaafiyaa, which is a repeating pattern of words.
The following is an example of a Ghazal by Daag Dehelvi. In this example the Radif is mein. The Qaafiyaa is the following pattern of words: nigaah (in the first hemistich), jalwa-gaah, nigaah (in the fourth hemistich), raah, haale-tabaah and aah.
aafat kii shoKhiyaa.N hai.n tumhaarii nigaah mein
mehashar ke fitane khelate hai.n jalwa-gaah mein
wo dushmanii se dekhate hai.n dekhate to hain
mai.n shaad huu.N ke huu.N to kisii kii nigaah mein
aatii baat baat mujhe yaad baar baar
kahataa huu.N dau.D dau.D ke qaasid se raah mein
is taubaah par hai naaz mujhe zaahid is qadar
jo TuuT kar shariik huu.N haal-e-tabaah mein
mushtaaq is adaa ke bahot dard-ma.nd the
ae DaaG tum to baiTh gaye ek aah mein
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.
The radifs for tar are one of the most famous radifs associated, with many old melodies collected that include 20-40 goushes in each dastgahs.
The Radif of Mirza Hossein-Qoli is the oldest radif which is still in use for many students who wish to carry on learning Persian music. It is very famous as it consisted many melodies collected from Mirza Hossien Gholi's time and before. Many of the melodies where changed by Mirza Gholi and some kept same to the composer's desire, but the evidence is small to suggest melodies were changed or not, but due to Radif being passed down through oral tradition(not in notation) we cannot state whether melodies were changed as we cannot compare Notations or audios, but due to the mutations in music through oral transfer it is obvious.
One of the most notable Tar players and repertoire of Mirza Hossien Gholi's Radif was Ostad Ali Akbar Shahnazi, who was the son of Mirza Hossien Gholi and was the first Tar player to record the Long Radif memorized by heart. His work is still used by many Masters and are now some directions which are followed by many Tar players. Of course Beginners-Intermediate students will not be able to follow his works on audio due to the Level which it was performed at, so not much will be understood, but a Tar Master can expect to use it and re-focus on what was forgotten in his teachings at lesson with students. This can minimize mutations and keep the radif in line.
The Radif was first published in notation by Dariush Pirniakan in the past 4 Decades and upgraded a few times due to errors. Though the radif is not popular with many young students it still is the consistute and basic of Persian music. It can be related to Classical music of western music that is not much popular, but forms the basic of Western Music.