Prince in the film Purple Rain Photo: WARNER BROS
When Warner Bros gave the greenlight for Prince to make the Purple Rain film they did so with some trepidation, writer Matt Thorne says.
Thorne, the author of Prince: The Man and His Music, says similar projects in the past had flopped.
"There was a film with Paul Simon called One Trick Pony that came out about four years before, which was the life of Paul Simon as a musician. And that didn't really go over, that didn't really work ... as a film. And it's almost forgotten today," he told Music 101's Charlotte Ryan.
'The summer of Prince': 40 Years of Purple Rain
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But the diminutive pop genius was on top of the world at the time, and what Prince wanted, Prince got, he said.
"He'd reached a point with the 1999 album, and then the Triple Threat Tour that he just couldn't get any bigger. And he'd reached that point in his contract with his management, and I think with the studio as well, where he was ready to leave.
"He said to them, unless you go and get me a film, and give me the ability to make a film, I'm going to leave, and everybody thought he was crazy."
The film was a huge hit, and in 1984 Prince became the first artist to have a top movie, a top album, and also top single at the same time.
Purple Rain was like a cottage industry, Thorne said, Prince assembled the cast and crew at his base in Minneapolis.
The inimitable Prince, image from Purple Rain Photo: Supplied
"These weren't well-known professional actors, they were his friends and other musicians. They're all brilliant, everybody in the film is fantastic. But it's that thing of just going to your hometown and getting the world that's there and turning it into a cinematic vision.
"And managing to remain friends with almost everyone that was in it. I mean, there were a few rivalries, a few jealousies, but it's pretty extraordinary."
Seen through contemporary eyes the 40-year-old film is problematic to some, he said.
"I don't think the film's misogynistic, I think there are actions within it that are misogynistic, but they're part of the story and part of the drama."
Prince also revealed a vulnerability within himself as the character The Kid, he said.
"The film is not just him in competition with [rival band featured in the film] The Time, it's him in competition with all the other musicians around him, and yet he's written all the music, so it's him in competition with himself.
"And I think there's something quite brave about showing that darker side of his personality within a fictional scenario."