Ahmir “Questlove” Thompson will direct “Black Woodstock,” a feature documentary about the Harlem Cultural Festival, Variety has learned.

Held in 1969, the outdoor festival featured performances from some of the leading black musicians of the day — a group of heavy-hitters that includes Sly and the Family Stone, Stevie Wonder, Nina Simone, B.B. King, the 5th Dimension, David Ruffin, Mahalia Jackson, the Staple Singers, and Gladys Knight and the Pips. The festival took place one year after the death of Dr. Martin Luther King Jr, and was intended to celebrate African American culture and politics, as well as to promote black pride and unity.

It unfolded in Harlem’s Mount Morris Park during the same summer that Woodstock captured the attention of the world. Despite drawing over 300,000 people, the Harlem Cultural Festival received virtually no coverage from mainstream media, a staggering omission that Thompson’s film hopes to rectify. “Black Woodstock” will include 40 hours of never-seen-before footage originally shot by late television pioneer Hal Tulchin. It has remained in storage for half a century. The title of the movie is derived from the term that Harlem residents used to describe the festival.

“I am truly excited to help bring the passion, the story and the music of the Harlem Cultural Festival to audiences around the world,” Thompson said in a statement. “The performances are extraordinary. I was stunned when I saw the lost footage for the first time. It’s incredible to look at 50 years of history that’s never been told, and I’m eager and humbled to tell that story.”

“Black Woodstock” marks Thompson’s directing debut. He is a drummer, DJ, producer, culinary entrepreneur, best-selling author of Mo’ Meta Blues and Mixtape Potluck, and member of hip-hop group The Roots. He also serves as the musical director for “The Tonight Show Starring Jimmy Fallon,” with the Roots crew serving as house band for the late night program. Beyond that, the musician’s indisputable reputation has landed him musical directing positions with everyone from D’Angelo to Eminem to Jay-Z.

“Black Woodstock” will be produced by David Dinerstein and Robert Fyvolent (“Cries From Syria”; “Winter On Fire: Ukraine’s Fight For Freedom”) with RadicalMedia (“What Happened, Miss Simone?”) coming on board as creative and production partners. Jon Kamen and Dave Sirulnick will serve as executive producers. The film is co-produced by Vulcan Productions. Concordia Studio, Play/Action Pictures and Beth Hubbard will also serve as executive producers. Joseph Patel will serve as a producer with Joshua L. Pearson (“What Happened, Miss Simone?”) on board as editor and Randall Poster (“Grand Budapest Hotel”) as the music supervisor.

“The music and performances in ‘Black Woodstock’ will knock audiences out of their seats,” said producers Dinerstein and Fyvolent. “The footage is unusually rich in texture and feel. We are so proud to be working alongside Ahmir ‘Questlove’ Thompson on his directorial debut. We are confident he will bring an authenticity and unique vision to the film. We are thrilled to partner with some of the best people and organizations working in the documentary space today including Vulcan Productions, Concordia Studio, Play/Action Pictures and RadicalMedia.”