NEW YORK (AP) — Spike Lee worked with Michael Jackson and considered him a friend, but the director says even he learned a lot combing through footage of the icon for a planned documentary about the singer’s Bad album.

Lee calls it a “treasure chest of findings.”

Spike Lee

“We have footage in this documentary that no one’s ever seen, stuff that Michael shot himself, behind-the-scenes stuff,” he said in an interview Monday. “We had complete access to the vaults of Michael Jackson. … He wrote 60 demos for the Bad record. Only 11 made it. So we got to hear a lot of that stuff, too, so it was just a great experience.”