While Prince's concerts were designed to be celebratory and joyous, he was nonetheless fully capable of sneaking a topical message into his shows. Take "The Second Coming," for instance. The two-minute a cappella track was used as the introductory music before dates on his Controversy tour.

It features Prince as a one-man gospel choir sermonizing about the need for everybody to love each other before the arrival of the Messiah. In the bridge, he sings "How many more good men must die before there's gun control / U've got 2 love your brother if you want 2 free your soul." You can check it out below, and hear it segeuing into the proper set opener, "Uptown."

The "Second Coming" title was used as the name for one of Prince's most talked-about unreleased projects: A movie that was kind of a precursor to Purple Rain. He was looking to record one of his concerts for either television or home video. His management hired Chuck Statler, who was hired to direct the Time's video for "Cool" on the strength of his clip for Devo's "Whip It." They filmed Prince's March 7, 1982 show at the Met Center in Bloomington, Minn.

Statler told WaxPoetics that as they were looking at the footage, Prince came up with a bigger idea: To create a somewhat autobiographical story around the concert and turn it into a full-length feature film, much as Led Zeppelin had done with The Song Remains the Same.

But the project was never completed. Statler called the process of making the movie a "gruesome drill. The filming went on and on…being the perfectionist and control maestro that he is. We were trying to be as efficient as possible, but it became one thing after another, which delayed the whole process instead of doing quite the opposite. All the shots we talked about and all the camera blocking we did, the storyboards, the pre-production."

An example of this came late in a day's shooting. They were trying to get a fairly simple shot of Prince chewing gum and blowing bubbles, but it still turned into a big problem. "After about so many takes I say, 'Okay, we got it. Let’s go on to the next shot,'" Statler continued. "Prince looks at me and says, 'No—I’ll tell you when we got it.' Now there might have been some minor rubs before that, but it was at that moment…I said, Okay—if that’s the way you want it.'"

Prince shelved the project after the first round of shooting. Years later, Statler and Prince came to a deal for the concert, but Statler has retained the other footage that was shot. Still, as difficult as that time was for him, Statler believes that his movie could have been as big as Purple Rain.

"There’s little question in my mind that The Second Coming would have enjoyed commercial success," he said. "I know it’s easy to say now, but the Artist and his music was/is too compelling and powerful. His music is undeniable, and the odds are much better that it would have garnered a large audience. It was the right idea at that point in time. It would have had a reach well beyond what his touring could provide. It’s difficult for me to estimate its critical appeal because the premature abandonment left a large portion of production and the project unfinished and unrealized. It had potential. But it’s just something that’s in his vault, and that’s as far as it will ever go, most likely."