TANTA, Egypt - The din rises above the main square of this Nile Delta city. Near the mosque, crowds jostle at claustrophobic density for blocks, illuminated by lights that make every building appear to be hosting a wedding simultaneously.
Mixed in the wall of sound is the crowd chatter, the blaring music, and the shrill microphones of the hawkers selling toys, party hats, jewelry, smoked fish, and sticky sweets. Somewhere - nearly submerged in the chaos - is the faith, generosity, and infectious communal vibe that makes it all possible.
The raucous setting was the country's largest moulid, or religious festival, one of the cornerstones of Egyptian Sufism - the mystical segment of Islam with an estimated 6 million Egyptian followers. Each summer and autumn, Egypt's urban neighborhoods and rural villages play host to a series of such festivals.
In Western terms, the moulids are a hybrid of a rural evangelical tent revival, a Grateful Dead show, and Mardi Gras.
Sufism is practiced throughout the Muslim world, but the Egyptian moulid tradition has developed into a phenomenon. Some speculate that Egypt's moulids are a mixture of Sufi tradition and ancient Pharaonic celebrations - a perspective reinforced by the fact that Egypt's Coptic Christian population hosts its own moulids.
But for something that is, at its heart, a religious festival, a solid 75 percent of the activities at any given moulid seem to have very little to do with religion. This year's festival in Tanta was held from Oct. 15 to Oct. 18.
''People come for the party, to get drunk, to make some noise. Some of them even come for religion,'' Mahmoud, a 60-year-old Ministry of Irrigation employee, said recently while sitting in a packed coffee shop facing Tanta's Sayyed Badawi Mosque. The mosque was named for the 13th-century holy man and spiritual father of Egypt's largest Sufi order.
''Three-fourths of these people are like me. I come for a change and some fun ... to see friends that I only see at moulids,'' Mahmoud said.
All of which is just fine for Ali Darwish, a sheik in the Shazliya Sufi order. Darwish, who works in the press office at the US Embassy in Cairo, acknowledges that the vast majority of modern Egyptian attendees are either out for a good time or looking to sell something.
''That's the way it is with every human activity. There's the center, and there are the waves of activity around it that often have nothing to do with the center,'' he said.
''There's people who come to make money. There are people who come to have some fun,'' Darwish said. ''It's not a problem. It all adds to the joviality.''
At most moulids, the spiritual and the temporal coexist. The sheer size of the affair at Sayyed Badawi - the country's largest, with an estimated 1 million participants - means that the ''center'' of the moulid actually takes place along the edges. From the Sayyed Badawi Mosque, it's a solid hour's walk through choking crowds to the field on the edge of Tanta where the religious events are taking place.
Along the way one passes dozens of hastily assembled sales booths, shooting galleries, carnival tests of strength, bumper cars - even a few freak shows promising magic, levitation, and the chance to view two-headed cows.
At the end of the carnival road lies a massive open field, ringed by the brightly colored enclosures of the Sufi orders. The tents play host to charity tables, passing out food and drink to all comers, and to the zikr - the marathon sessions of music, swaying, and chanting that help the Sufi attain a mystical state of joy and unity with God.
Sufism in modern times enjoys a complex relationship with the state. The movement has the stamp of approval in the form of the Supreme Council of Sufism, and no Badawi moulid is complete without a few government dignitaries coming to pay their respects to the saint. Former president Anwar Sadat made regular appearances at the Tanta festivities.
But the country's increasingly austere religious sensibilities regard Sufi mainstays, such as the veneration of saints and the belief in miracles, to be a corruption of Islam. As a result, government expressions of approval must be slightly muted.
Apart from the religious objections, the Sufi traditions also suffer from a certain, largely class-based misperception. The practice of moulids is considered backward village superstition among most middle- and upper-class Egyptians.
In the 1999 book ''Moulid! Carnivals of Faith,'' essayist Tarek Atia wrote, ''The sheikh's feasts that dot the average Egyptian social calendar remain a mystery to the wealthier, more modernized citizens of this ancient land, as well as to a growing number of urban and rural Muslims who have come to understand that such celebrations actually go against the grain of the religion.''
Darwish shrugs off questions about Sufism's detractors.
''Sufism is the spirit of Islam.... It makes you a wonderful human being,'' he said. ''You can't be arrogant. You can't be selfish. You can't be cruel.''