Avaz, or Awaz (Persian: آواز) is unmetered vocal section of a mode in Persian music.
In the years 1965 and 1966 Mahmoud Karimi (maestro of Persian vocal music) performed the whole Avazs which were recorded and transcribed by Mohammad-Taghi Massoudieh. This version was published in 1997 in Tehran.
References
Avaz (music) Wikipedia(Text) CC BY-SA