As the US boiled with violence, 1969’s Harlem cultural festival nourished spirits with soul, jazz and gospel. Now, Questlove has turned lost footage of it into a brilliant, pertinent documentary

It’s 29 June 1969, and at Harlem’s Mount Morris park (now Marcus Garvey park), the 5th Dimension are about to take the stage. The Los Angeles group are already stars, thanks to hits including Up, Up and Away and Aquarius, from the musical Hair, which topped the Billboard charts that spring. But their pop-oriented repertoire, often penned by white songwriters, has kept them off the US’s R&B radio stations and thus from Black audiences. “We’d tried to separate ourselves from the segregation in our society, but we still got caught up in all that,” remembers the group’s founding singer, Billy Davis Jr, today. “And the average Black family didn’t earn enough to come see us at the nightclubs we were playing. They’d seen us on TV, but they’d never seen us live.”

That was about to change with their headline performance on the opening day of the Harlem cultural festival. A series of six Sunday concerts that summer, the festival showcased the cream of the era’s soul, gospel, blues and jazz artists before an audience of 300,000, many from the surrounding neighbourhoods. “I looked out and saw a sea of faces, and their response was so loving, so welcoming and exciting,” says Davis Jr’s wife and bandmate, Marilyn McCoo, for whom the festival remains a treasured memory. She’s not alone. Harlemite Musa Jackson, then just a five-year-old, still remembers how the 5th Dimension’s orange costumes, gleaming in the sun, made them look “like Creamsicles”.