“When You’re Strange,” director Tom DiCillo’s documentary about the Doors, will open theatrically April 9.

If you’ve followed the life of the film, like many documentaries, it has had an interesting birth. “Strange,” which DiCillo says is a combo between a documentary and a narrative, screened at the Sundance Film Festival in 2009. But it took on a new life after Johnny Depp agreed last spring to narrate the piece. The film was produced by Wolf Films/Strange Pictures, in association with Rhino Entertainment. Rhino, which has the Doors’ musical catalog, will release the soundtrack on March 30.

While Oliver Stone directed a biopic about the band, starring Val Kilmer as Jim Morrison, this marks the first feature documentary about the Doors and includes previously unseen footage.

I interviewed DiCillo last year after the film for a piece in Variety and we discussed Morrison’s enduring magical aura that combined danger, sex and art. “[Morrison] was the first to really do that,” DiCillo said. “Elvis was pretty and sexy, but he wasn’t a poet. Jagger was a little dirty, but he wasn’t mythological.”

Of course, part of Morrison’s appeal is that he’s also dead. And while, like Elvis, he had his periods of bloat, the image most of us hold of the Lizard King is the iconic, tortured, impossibly beautiful man shirtless and in leather pants.

For feature director DiCillo, his mandate for his first documentary was that he present a new side to the Doors. “What I most definitely didn’t want to do was paraphrase everything already said about the Doors,” he said. “I [had] to find something personal about this band that hasn’t been said before. That’s what made it very, very challenging. I present Jim Morrison and the band in the way that no one has before. We see them as very human.”

Meanwhile, Depp is quite the music fan. He is now working on a documentary about Keith Richards.