Charkha was a most popular qwalli of Ustad Nusrat Fateh Ai Khan Which is Most famous among people till now. A qawwal is a specially-trained male vocalist who performs qawwali, a musical expression of devotional poetry practiced by the Sufis. The Sufis, an ancient mystical sect of Islam, achieve spiritual enlightenment through music, much like a Whirling Dervish achieves a higher state of consciousness through dancing.