Four Sufi orders shaped Punjab: the Chishti, the Suhrawardi, the Qadri and the Naqshbandi. Between them they account for most of the shrines in the province and most of its Punjabi devotional poetry.
The Chishtis, whose practice included music and openness to non-Muslims, took root deepest. Baba Farid Ji at Pakpattan is Chishti. The Suhrawardis centred at Multan under Bahauddin Zakariya. The Qadris produced Shah Hussain, Bulleh Shah's murshid Shah Inayat, and Sultan Bahu. Mian Mir of Lahore, a Qadri, is the man Sikh tradition says laid the foundation stone of the Harmandir.
Their shrines were and are visited by everyone. A Sikh or Hindu family taking a vow at a local pir's grave was entirely ordinary and in many villages still is.
In Indian Punjab the shrines lost their custodians in 1947 and many were destroyed or converted. Those that survived are often maintained by Sikh and Hindu villagers who keep the lamp lit without knowing much about the man.
Punjab's Sufi poetry is read by Sikhs in Gurmukhi and by Muslims in Shahmukhi and it is the same poetry.
The urs is the anniversary of a saint's death, kept as a wedding, and it was the calendar the countryside actually ran on. Pakpattan's, Multan's, Lahore's and the small ones at village graves gave the farming year its fixed dates, and each was a fair and a market and a gathering as much as a devotion.
The following at them was mixed. Hindu, Sikh and Muslim families vowed at the same shrines and the vows were about the same things: a child, an animal, a recovery, a journey.
What crossed over was the poetry. Bulleh Shah, Shah Hussain, Sultan Bahu and Baba Farid Ji are read in Gurmukhi by people whose families have not been inside a dargah in three generations. The kafi survived on this side of the line when the shrine and the custodian did not.