"The Most Popular Music Festival You've Never Heard of"

"It was 'hotter than hell' at Sly and the Family Stone's July performance, according to the band's saxophonist Jerry Martini, who can still vividly recall specifics of that afternoon: The band's drummer, Greg Errico, performed with the flu, and the Harlem crowd did not immediately take to the band's funk-rock fusion. 'They were a tough audience,' says Martini. 'We didn't go over real well in the beginning. People weren't real familiar with our style in 1969. We weren't a conventional Harlem soul band or anything like that. We really had to work for it that day.'"

Jonathan Bernstein at Rolling Stone tells the story of the 1969 Harlem Cultural Festival.