Musicians, performers, songwriters, and their management/legal teams sue each other all of the time, mostly over that vague and nebulous concept known as “copyright infringement.” A few words in the lyrics, a couple of key chord progressions, and even a sequence of a few notes may sound similar enough to a previously-written work that the original writer believes someone has copied them, and they need to be compensated.

Back in the 1980s, Prince wasn’t the only member of his family involved in the music business. His half-sister, Lorna Nelson, as well as other members of the family, were also in the biz, according to UPI. To make an extremely long story short, Lorna had written and copyrighted “What’s Cooking in This Book,” and she believed that her half-brother’s song, “U Got the Look,” was close enough to hers that he’d copied her, and she wanted some money. U.S. District Judge David Doty determined that there were no substantial similarities between the two songs and dismissed the case.

But that wasn’t the end of the story. As the Los Angeles Times reported, Lorna took her case all the way to the U.S. Supreme Court, which ultimately decided not to hear the case.