Qawwali is an effervescent devotional musical form of the Sufis practiced in Indian sub-continent with the lineage stretching more than 700 years. Other than being practiced in Sufi shrines in India and Pakistan, the music has also gone mainstream with the work of Qawwali maestro Nusrat Fateh Ali Khan. Qawwali repertoire mostly comprises Urdu and Punjabi songs with the vital theme of the songs ranging from love, devotion and longing for God. Qawwali musicians consist of 8-9 men with one lead singer and harmoniums, dholak and tabla being the key instruments. The songs begin gently developing high energy levels gradually to stimulate hypnotic state of mind of the listeners and the musicians. Qawwali is also often used in Bollywood music.