She has the exhilarated smile of someone being swung through the air by her dance partner. A disco ball reflects the flash of the camera. It's around 1979, and Cyndy Booker is dancing at the Taste Show Lounge.

The man taking the photograph is Charles Chamblis, a familiar figure at this Minneapolis club. During the 1970s and '80s, "the Pictureman" was rarely seen without his camera. He was "always everywhere," snapping moments like this, according to Thornton "T.J." Jones, then of KUXL's "The Pharaoh Black Show." "He was an integral part of our community."

Today, with the ubiquity of cameras, it's hard to grasp the importance of Chamblis, who died in 1991. The Pictureman performed a service now taken for granted: preserving the happiest moments of leisure and music.

In "Sights, Sounds and Soul," an exhibit opening Saturday at the Minnesota History Center, you can see Prince with an Afro, Terry Lewis in a homemade superhero outfit and Cynthia Johnson in the same photo (in her band with Lewis, Flyte Tyme) before she recorded "Funkytown," wearing a green headdress cut from her Miss Black Minnesota USA gown. You can also see kids wading in Lake Calhoun, fashion models walking and men laughing over barbecue.

Chamblis' legacy, which includes more than 2,000 photos in the Historical Society archives, is nothing less than a document of the Twin Cities African-American community at play, during the heady decade before "Purple Rain." It's a window on creativity in de facto segregation, when interracial bands such as Paul Johnson's Runway couldn't get gigs at clubs catering to whites. Instead they turned to a circuit that included the Taste, where the group — in one Chamblis photo — jumps and cowbells in matching shiny uniforms.

"The perception is these are really rough places," says Jon Kirby of Chicago's Numero Group, which released the 2013 box set "Purple Snow: Forecasting the Minneapolis Sound," with a Chamblis photo (at the Taste) on the cover. "I think the photos dispel the wrong-side-of-the-tracks notion."

With another recent compilation also featuring Chamblis photos, "Twin Cities Funk & Soul: Lost R&B Grooves From Minneapolis/St. Paul 1964-1979" (on Secret Stash Records), the scene he loved only grows in fascination.

The Pictureman was as much a part of this world as Prince, whose gap in the archive can be explained by the fact that at one point, the musician bought all the pictures of himself from Chamblis.

The cameraman was familiar with everyone, and made everyone look familiar.

"We were so comfortable with him that it felt like we were doing a family photograph," says Cynthia Johnson. "I know he wasn't making a good living at it. He was doing what he loved, just like the rest of us."

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One reason there are so many Chamblis photos is the unusual business model he used.

When not freelancing for the Minnesota Spokesman-Recorder, Chamblis would take pictures, develop them and then track down the subjects in hopes of selling them. Which meant plenty of leftovers. The Chamblis archive is largely what he didn't sell.

"I just thought he was a very poor businessman because of the way he was doing things," says his youngest daughter, Reva Chamblis, who donated the photographs and who has an equal number at home. "Little did I know he was creating a huge collection."

Chamblis was born in Pittsburgh in 1927. He received an honorable discharge from the Marines after serving in World War II, and settled in Minneapolis with Reva's mom and two siblings. Though the parents divorced, Charles was still invited over to take pictures.

In high school, Reva decided to get to know her father: "I would just pop over and say, 'Hi, Dad. What ya doing?' "

Inside the house there were cameras, pictures and jazz records to the ceiling. "There was this small path that you had to use to walk from the door to the kitchen," Reva said. "He might have been a little embarrassed, but after a while, it was, 'Hang on a second, let me find you a space.' And he would move something so I could sit down."

Charles taught her how to use a camera, and he gave her advice. "You need to learn to smile with your eyes," he said.

Years later, when diagnosed with amyloidosis — a rare disease characterized by abnormal protein deposits in the body — the hard part for him was not having the strength to practice his art. He passed out twice before giving up.

"Am I going to have a garden this year?" he wrote in his datebook in 1982. "I take pictures of people — that is a garden to ME."

Chamblis flooded his images with something more than light: an interactive spirit.

"He'd say, 'Turn this way, give me a smile,' " said his friend Roosevelt Gaines. "He didn't like to take pictures where folks were all sad and depressed. Because there was a lot of sadness going on back in those days. He wanted to get the best shot of you that he possibly could."