Kim Parham remembers the days when she’d cook all the food for the picnic. She laughs when she recalls using a folding chair to secure their spot in the park behind the Museum of Science and Industry. Twenty-one years ago, she and five friends, now known as The Chosen Few DJs, met on the July 4th weekend, when they’d all be home. Their claim to fame in high school was as Chicago’s top house music DJs.

What started out as a house music reunion picnic with Parham, Wayne Williams, Alan King, Jesse Saunders, brothers Andre and Tony Hatchett, and about 40 family members and friends, has since grown into The Chosen Few Old School Reunion Picnic, the world’s largest event of its kind and the third-largest one-day event in Chicago.

“We never thought it would get this big,” says Parham, event director for The Chosen Few DJs. “Alan and I always say, ‘We are victims of our own success.’ Through a grassroots effort and word of mouth, we didn’t need promotion. A webcast was started last year. It’s amazing; people watch us all over the world. My girlfriend in Switzerland saw it.”

About 30,000 people—from as near as Detroit and St. Louis to as far away as Australia, France, Germany and South Africa—attended this year’s picnic in Jackson Park. People started lining up at 2:00 a.m. to prepare their tents and grills for the daylong event, which featured a lineup of 13 DJs and kicked off at 8:00 a.m.

Often referenced as the “Woodstock of House Music,” the event has transcended the fabled four-day peace and music festival held in 1969. Like Woodstock, it is peaceful; in fact, in its history, there has never been an incidence of violence. It’s a “love fest” and testament that African-Americans can come together—even in scorching temperatures—to unite as one without strife. Until three years ago, the picnic always took place during Fourth of July weekend but had to change because of The Taste of Chicago and straining city resources. Last year was the first time The Chosen Few ever charged admission, due to exorbitant expenses they could no longer pay out of pocket themselves.

“I never imagined it would grow to these proportions,” says DJ King, an attorney who played high school basketball with Arne Duncan, the U.S. Secretary of Education, and is one of President Obama’s hoop buddies. “It started out as a small gathering like a family reunion, and that’s one of the nicest things about it. We’ve got 20,000-plus people now coming from all around the world. and we still do everything in our power to keep it toward family.”

Williams founded the group in 1990. It was comprised of a group of popular DJs from Chicago’s South Side. Their turntable skills at high school events, basement house parties and legendary nightspots, including The Warehouse, won them notoriety around the city and, eventually, across the globe. Terry Hunter was invited to join the group six years ago.

“There’s a lot of behind-the-scenes work that goes into DJing, finding music and being competitive from that aspect,” says DJ Williams, senior vice president of Jive Records. “I think not only do you have to find it, you have to pick it and know exactly what your crowd is going to like. That takes a lot of talent, quite honestly, and I found it in all these guys.”

The annual event speaks to the power of turntable masters, who are able to pack the park with a form of music born in Chicago that morphed from disco.

“I have traveled from one end of this world to the next, and I can say we have the best DJs in the world in Chicago,” says DJ Hunter, internationally renowned for his remixing and producing skills. “I have seen situations in which DJs preprogram their sets for three or four records, someone else plays their songs, and they were taken out of their sets. It was a disaster. We know how to adapt to any situation.”

Already, the crew is planning next year’s event. “It’s a powerful thing to look out and see what seven people are able to do just trying to get good friends together,” says Parham. “People say we are entrepreneurs. We didn’t start out being that way. You just never know what you can do. The power of positive energy, music and friends can produce an amazing event.”