A vocal devotional singing style found across Pakistan, and northern India, associated with Sufi music with both Persian and sub-continental roots. A singer of this musical form is called a Qawwal and the performance is always in a group. The word Qawwali literally means 'utterances' in Persian and the present form of Qawwali is credited to be started by Amir Khusrau, a Sufi from Delhi. Derivatives of this form have become a key element of the popular music of India and Pakistan. The word is also written kawali, kawwali, and in other variations in Roman script.