Spike Lee has made many groundbreaking films throughout his career, but none may be as closely-watched as his latest project: a documentary about Michael Jackson.

Lee said he was friends with Jackson, and learned more about Jackson by doing the documentary.

“I’m more than just a huge fan of Michael Jackson,” Lee told Rolling Stone. “And having the chance to actually know him and work with him, I deeply care about his legacy.”

The documentary will mark the 25th anniversary of Jackson’s groundbreaking “Bad” album. Lee told the Associated Press that much of the footage featured in the film was shot by Jackson himself as he worked on that album. Lee said audiences will not only see how Jackson made his music, but they’ll also see a bit of his personality.

“He had a great sense of humor, and he was funny—so you’ll see a lot of that stuff,” he told the AP.

According to reports, Lee interviewed several artists for the documentary including Kanye West, Mariah Carey, and L.A. Reid. Lee told the AP that his interview choices were intended to show which artists were influenced by Jackson and how his record label was committed to making the album work.

According to Rolling Stone, the documentary will accompany the September release of a box set celebrating the 25th anniversary of “Bad.