Common knowledge has long held that "The Beautiful Ones" was written for Prince's former girlfriend Susannah Melvoin. Engineer Susan Rogers, for one, has confirmed it.

The timeline certainly fits: Susannah, the twin sister of Revolution guitarist Wendy Melvoin, was seeing someone else when she met Prince in May 1983. But even Melvoin has admitted that she isn't completely sure about the genesis of "The Beautiful Ones."

"I can't say that the song was exactly our story, but he wrote it during that time," Melvoin says in Let's Go Crazy: Prince and the Making of 'Purple Rain.' "He wasn't always specifically writing about what he was going through, because he also had to be consistent with the Purple Rain storyline, but he was drawing from things that had happened in his life."

Only much later, during a 2015 interview with Ebony magazine, did Prince finally make clear just who the beautiful one really was: Vanity, his one-time protege.

She had originally been cast in Purple Rain, playing the female lead in the midst of a love triangle between characters played by Prince and Morris Day, but then split with Prince shortly before production began. Apollonia replaced her in the cast.

Both elements, the actual and the imagined, are at play in this layered triumph. "I was talking to somebody about 'The Beautiful Ones.' They were speculating as to who I was singing about – but they were completely wrong," Prince said. "If they look at it, it’s very obvious. 'Do you want him or do you want me,' that was written for that scene in Purple Rain specifically, where Morris would be sitting with [Apollonia] and there’d be this back and forth. And also, 'The beautiful ones you always seem to lose,' Vanity had just quit the movie."

Prince originally ran into Vanity, whose real name was Denise Matthews, at the 1980 American Music Awards. They began dating, and Prince invited her to front an all-girl group he was assembling in Minneapolis. Vanity 6 found immediate, if short-lived, success. Their first single, "He's So Dull" appeared in National Lampoon's Vacation. Their second, "Nasty Girl," rose to No. 7 on the Billboard R&B charts, while Vanity 6's debut album went gold.

They opened a 1982-83 tour with Prince and the Time before Prince cast Vanity in Purple Rain. She appeared with him on the cover of Rolling Stone.

Then the wheels fell off. Vanity got offered a lucrative solo deal by Motown Records, decided to bolt – and her romance with Prince suddenly ended.

He later began a relationship with Susannah Melvoin, and she ultimately became something like a muse. Melvoin inspired "Nothing Compares 2 U," which became a smash hit for Sinead O'Connor; "Big Tall Wall," from the shelved Dream Factory album; the similarly unreleased "Wally"; and perhaps "Condition of the Heart" from Around the World in a Day. Susannah was also deeply involved in the creation of Sign O' the Times (the co-written "Starfish and Coffee," "Forever in My Life," "If I Was Your Girlfriend").

"We were very attached," Susannah said in Let's Go Crazy, "and he spoke a lot through music. He would come and play me something, and I knew perfectly well it was about me."

But not this time. Instead, "The Beautiful Ones" blends his initial feelings about a painful real-life split with the invented movie-script arc for Apollonia. "It’s not about somebody human that I’m looking at right now," Prince told Ebony. "It wouldn’t have worked if it was. This was literally for that character. And that’s why it worked."

Vanity's tragic death in 2016 – she suffered kidney failure after years of earlier crack cocaine abuse – brought her role in this song's creation back into sharp focus for Prince.

He dedicated "The Beautiful Ones" to Vanity during the first show of a solo Australia tour, just days after her passing. "Her and I used to love each other deeply," Prince said from on stage in Melbourne. "She loved me for the artist I was; I loved her for the artist she was trying to be."

When he got to "I'm begging down on my knees," one of the song's most tortured lines, Prince ad-libbed "Denise."

Prince Albums Ranked in Order of Awesomeness