(Photo courtesy of Mass Distraction Media / Sundance Institute) Sly Stone performs in 1969 at the Harlem Culture Festival, the subject of Ahmir "Questlove" Thompson's documentary "Summer Of Soul (Or, When The Revolution Could Not Be Televised)." Sundance Institute, as part of its summer For the Locals series, will host free screenings of the movie on July 14, 2021, at the Utah Olympic Park in Park City, and July 16, 2020, at Salt Lake City's Red Butte Garden Amphitheatre.