Nusrat was responsible for the modern evolution of qawaali. Although probably not the first to do so, he popularized the blending of khyal singing and techniques with Qawaali. This in short took the form of improvised solos during the songs using the saregam technique which the performer sings the names of the notes he is singing (for example in western notation it would be "do re re mi".) He also attempted to blend Qawwaali music with more western styles such as techno.
According to the Guinness Book of World Records, Nusrat Fateh Ali Khan holds the world's record for the biggest recording output by a Qawaali artist (a total of 125 albums of recorded music).
His early career is the subject of a documentary film made in 1997 entitled Nusrat Has Left the Building...But When?
After Nusrat passed away in 1997, his nephew Rahat Fateh Ali Khan took up his torch and followed in his footsteps as a singer.