Rang or Aaj Rang Hai Ri Maan Rang Hai Ri, (Hindi: रंग, Urdu: رنگ ) "Color" / "Today There Is Color, Oh, Mother" is a poem by the famous medieval Sufi poet and scholar Amir Khusro, regarded as the "Father of Qawwali"
The poem tells how Khusro comes back home after having found his spiritual guide, Sufi saint Nizamuddin Auliya, and describes the experience to his mother.
The lyrics performed in this video are an arrangement of that ancient poem, mostly respecting the essence of the original.
It was written in a mixture of Hindustani and Braj or "Braj Bhasha", a North Indian dialect that still exists today, much diminished, but was a major literary choice in medieval times.
This is a style of qawwali called "kalam", in which tempo and intensity increase as the music progresses, to symbolize the mystic trance of the singers.
The performers are two famous Pakistani singers: Rahat Fateh Ali Khan, and Amjad Sabri.
Both belong to families of qawwali singers (Nusrat Fateh Ali Khan and Sabri Brothers), who also had performed this particular piece together, decades before.
Tragically, this one turned to be one of the last public appearances of Amjad Sabri, he was murdered by extremists shortly afterwards.