Qawwali has been a part of music culture for a long time , it has even been adopted in several films . At one point almost every Bollywood film had one .It is loved by many , let us take a look at what Qawwali is .

Qawwali is a form of Sufi Islamic devotional singing, originating from the Indian subcontinent, and notably popular in the Punjab and Sindh regions of Pakistan in Hyderabad, Delhi and other parts of India, especially North India, as well as the Dhaka and Chittagong Divisions of Bangladesh.

The songs which constitute the qawwali repertoire are primarily in Persian, Urdu, Hindi, and Punjabi. There are some in Persian from the Mughal era,and a smattering in Saraiki and dialects of north India like Braj Bhasha and Awadhi. There is also qawwali in some regional languages but the regional language tradition is relatively obscure

Source wikipedia