Nusrat Fateh Ali Khan, born Anjum Pervaiz Ali Khan, was a legendary Pakistani vocalist and musician, primarily a singer of Qawwali, a form of Sufi Islamic devotional music. Widely considered one of the greatest voices ever recorded, he possessed an extraordinary range of vocal abilities and could perform at a high level of intensity for several hours. Extending the 600-year old Qawwali tradition of his family, Khan is widely credited with introducing Qawwali music to international audiences. He is popularly known as "Shahenshah-e-Qawwali", meaning "The King of Kings of Qawwali".