For decades, it's been a thing to try to pit Michael Jackson and Prince against one another. Who was better in the battle of royalty — the King of Pop or His Purple Majesty?

Both musicians had other-worldly charisma and skill. Both could dance. Both made fans people squeal and pass out. Both loved James Brown and glitter. And both were a little alien-like in their celebrity: They were human but like, not.

It's natural that people wanted the two musical giants to collaborate. That, however, never happened, even though it could've way back in 1987, when Jackson wanted Prince on the song "Bad," and Prince declined to participate. When you look at the history between the two mega-stars, Prince's refusal isn't shocking.

Early on in their careers, the comparisons were pretty inevitable. For years, their careers ran parallel, beginning in the late '70s when Prince dropped For You in 1978. The record came out just one year before Michael Jackson's solo breakthrough, Off The Wall. In 1982, Jackson released his huge, record-breaking album, Thriller, reigning solo in the pop music spotlight until Prince came back with 1984's hit movie and soundtrack, Purple Rain (both albums were recorded in the same Los Angeles-based home studio). The record caught Jackson's attention, and he even attended a string of Prince's shows when he came into Los Angeles for the Purple Rain tour.

Already, some sort of competition or rivalry—verbally acknowledged or not—was brooding between the two. You can see it pretty clear during a James Brown tribute in 1983, when Michael Jackson calls Prince up to the stage, and Prince gets all weird, then tries to steal the show by ripping off his shirt and screaming into the mic.

Watch Michael Jackson and Prince at the James Brown Tribute

"It was just very obvious what the hell happened — [Prince] made a damn fool out of himself," Quincy Jones told GQ. "Michael went up there, in 40 seconds, sang 'I love you, I love you.' Then they went up-tempo and he did a little dance and did the moonwalk and whispered in [James Brown's] ear, 'Call Prince up — I dare him to follow me.'"

But that's not all. When Michael and Prince shared a studio, their rivalry extended to the ping-pong table (apparently, ping-pong was a thing for Prince). Prince won the match and reportedly said Michael "played like Helen Keller." They also played basketball at Paisley Park.

“Prince had a deep-seated competitive nature, so it’s easy to see where he would measure himself against Jackson’s success," The Revolution's Bobby Z told the Minneapolis Star Tribune in 2009.

Even though in the early-mid '80s particularly, their career trajectory was similar, and they knew one another, they never connected musically, though Jackson tried. First came 1985's plight to save Africa from AIDS, "We Are the World," which featured almost everyone who was alive and making music at the time. Michael wanted Prince, who was riding high off the success of Purple Rain, on the sappy song. Prince reportedly thought the song was corny, much to Jackson's chagrin.

“[Prince] felt like the song was horrible,” the Revolution's Wendy Melvoin told author Alan Light for his book Let’s Go Crazy: Prince and the Making of Purple Rain. “And he didn’t want to be around ‘all those muthafuckas.”

Watch Prince Discuss the Rivalry With Michael Jackson

By the time Jackson's 1987 "Bad" offer rolled around, it was a definite no-go for Prince. In a 1997 interview with Chris Rock he hilariously detailed exactly why.

“That Wesley Snipes character? That would have been me. Now you run that video in your mind," Prince told Rock, also adding that there'd never been a rivalry between him and Jackson, in his mind at least. "The first line of that song is 'your butt is mine.' Now I'm saying, 'Who's gonna sing that to whom? Cuz you sure ain't singing it to me, and I sure ain't singing it to you.' So right there, we got a problem."

In the end, "Bad" went on without Prince, Wesley Snipes became a huge star, and the Bad album has sold 35 million records worldwide. And as for Prince? Well, he kept his musical integrity and remained music royalty.

Watch the Video for Michael Jackson's 'Bad'

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