Michael Jackson and Paul McCartney first met and became friendly in the mid-1970s, when, according to Jackson, McCartney tried to sell him a song, "Girlfriend," for Jackson's upcoming solo album. Although it took a couple of years (and McCartney released the song first with Wings), the two hit it off, and over the next few years, they collaborated on a number of duets. The lead single off of Jackson’s smash album, Thriller (1982), was "The Girl Is Mine," a duet he penned while watching cartoons with McCartney. Likewise, McCartney’s album Pipes of Peace (1983) had two songs featuring Jackson, "The Man" and "Say Say Say." The two superstars even filmed a music video for "Say Say Say," playing traveling vaudevillians who peddle their "Mac and Jack Wonder Potion" to unsuspecting townspeople.

During this time, McCartney reportedly explained to Jackson about the lucrative nature of music publishing. For complex legal reasons, the Beatle had lost his stake in Northern Songs, the publishing company that he and John Lennon set up, in the late 1960s. Because he wasn’t profiting from his own songs’ publishing rights, McCartney told Jackson about how he had been purchasing other artists’ catalogues (such as Buddy Holly’s) as a business investment. McCartney explained to the future King of Pop that whoever owns the rights to a song’s lyrics and composition earns royalties every time that song plays on film, TV, the radio, in a commercial, or in a concert. According to McCartney, Jackson then jokingly told him "one day, I’ll own your songs."

With the help of his attorney John Branca, Jackson started buying the rights to '60s songs that he liked enough to dance to. In 1984, Branca told Jackson that music publishing company ATV was for sale. Owned by an Australian billionaire named Robert Holmes à Court, ATV owned the rights to 251 songs from the Beatles’ catalogue (as well as 4000 other songs and a library of sound effects). Branca asked Lennon's widow, Yoko Ono, who ran Lennon’s estate, if she was interested in teaming up with McCartney to purchase ATV. Ono said no and reportedly gave her blessing for Jackson (rather than a corporation) to own the songs. Branca then asked McCartney’s lawyer if McCartney wanted to buy ATV, and his lawyer said the catalogue was too expensive.

Branca offered Holmes à Court $30 million for ATV, but other people—including Virgin’s Richard Branson and music industry executives Marty Bandier and Charles Koppelman—were also bidding on the company. Going against the counsel from his group of advisors (including businessman David Geffen), Jackson told Branca to offer $40 million. Holmes à Court still wanted more money, but Jackson stood firm in his desire to buy ATV. "You can’t put a price on a Picasso … you can’t put a price on these songs, there’s no value on them," Jackson reportedly said. "They’re the best songs that have ever been written."

Branca offered $45 million and did a handshake deal with Holmes à Court in April 1985, but the ATV owner backed out. Branca—along with competing bidders Bandier and Koppelman—traveled to London to try to finalize an agreement; to seal the deal, Branca promised Holmes à Court that Jackson would perform in a charity concert in Perth, Australia and exclude the Beatles tune "Penny Lane" from the deal (so Holmes à Court could give that song to his daughter). In August 1985, after months of negotiations, Jackson paid $47.5 million to buy ATV.

McCartney was not pleased to learn that his supposed friend bought the rights to his songs. He wrote letters to Jackson about the purchase, but Jackson dismissed them all by saying it was just business. "He won't even answer my letters, so we haven't talked and we don't have that great a relationship," McCartney said in 2001.

In 1995, Jackson sold 50 percent of ATV to Sony for $95 million, a sale that created the music publishing company Sony/ATV. Today, Sony/ATV owns the rights to millions of songs by everyone from The Beatles and The Rolling Stones to Lady Gaga and Taylor Swift. In March 2016, seven years after Jackson’s death, Sony/ATV agreed to pay $750 million to Jackson’s estate to buy out his 50 percent share of the company.

But for McCartney, it's been a long and winding road. Though he's said in the past that it wouldn't make sense for him to pay for his own work ("The trouble is I wrote those songs for nothing and buying them back at these phenomenal sums …" McCartney once explained. "I just can't do it."), his tune may have changed. On December 15, 2015, he filed a termination notice with the U.S. Copyright Office, the first step required for an artist to get back the publishing rights to their songs.