When the late legendary qawwali master Nusrat Fateh Ali Khan first sang in the United States, his concerts weren’t so different from those he performed in his native Pakistan.

With ecstatic and hypnotic improvised songs based in the ancient poetry of Sufism, the mystic tradition of Islam, Khan electrified audiences for up to five hours. He died in 1997 at the age of 49.

“We had to start cutting performances shorter for people who don’t understand the languages of the music (Farsi, Urdu and Punjabi),” said Rachid Din, who was Khan’s manager and now works with the next generation in Qawwali: Rizwan-Muazzam Qawwali.