Freed from the constrictions of a label, Prince set up his online NPG Music Club in 2001 to have complete control over his music. Among the first collections of new material sent to subscribers was One Nite Alone… (Solo Piano and Voice by Prince), which was released on May 14, 2002 and featured a cover of Joni Mitchell’s “A Case of You,” whose title, in Princespeak, was listed on the credits as “A Case of U.”

Prince’s love for Mitchell was hardly a secret. The back cover of 1981’s Controversy contains a newspaper headline that reads “★ Joni ★” and the Time’s third album, Ice Cream Castle, was named after a lyric from her “Both Sides Now.” In 1985, he told Rolling Stone that the “last album I loved all the way through was [her] The Hissing of Summer Lawns.” Two years later, Sign O’ the Times’ “The Ballad of Dorothy Parker” finds the narrator and the titular character listening to Mitchell’s hit “Help Me” on the radio (the line could also be a sly acknowledgement of another of her songs, “You Turn Me On, I’m a Radio”).

Mitchell was aware of Prince’s affection. “Prince attended one of my concerts in Minnesota,” she told New York in 2005. “I remember seeing him sitting in the front row when he was very young. He must have been about 15. He was in an aisle seat and he had unusually big eyes. He watched the whole show with his collar up, looking side to side. You couldn’t miss him—he was a little Prince-ling. [Laughs.] Prince used to write me fan mail with all of the U’s and hearts that way that he writes. And the office took it as mail from the lunatic fringe and just tossed it! [Laughs.]”

Prince’s admiration for Mitchell had never waned. He was spotted purchasing a compact disc of her 1976 record Hejira only five days before his death. And while he had performed “A Case of You” dozens of times in concert dating as far back as 1983 — including the early show on April 14, 2016, his second-to-last performance — the take that appeared on One Nite Alone is, according to PrinceVault, the only time he ever tried it in the studio. Contrary to the album’s subtitle, Prince’s recording is fully fleshed out, featuring organ, bass, guitar, and background vocals (all played by Prince) and drums by John Blackwell. But the piano is the dominant instrument, with a lyrical, jazzy solo in the middle.

Mitchell’s original, found on her 1971 masterpiece Blue, features her on dulcimer, James Taylor on guitar and Russ Kunkel on drums. Like much of Blue’s material, the lyrics are believed to be based on the dissolution of her relationship with Graham Nash. But Prince is able to personalize it by removing the first verse, where she depicts the moment “just before our love got lost” with sarcasm, drinking and a homesickness for her native Canada.

By focusing only on the second verse, you can see why Prince was drawn to it. “I am a lonely painter / I live in a box of paints,” he begins in his falsetto, and the connection is obvious to even casual Prince fans. A notorious workaholic and perfectionist who built levels of mystique around himself to protect his privacy, it’s easy to believe that Prince saw himself as trapped in his own work. In that context, the chorus also points to a similar conclusion. Where Mitchell sang “I could drink a case of you, darling / And I would still be on my feet” to refer to Nash’s emotional hold on her, Prince could be singing it to himself, a man unable to break free from his own creation.

How radical was Prince’s interpretation of “A Case of You?” Revolution guitarist Wendy Melvoin told Vulture about a night where she and Prince had dinner at Mitchell’s house in Malibu. “So we’re on the couch, having these incredibly deep conversations with Joni Mitchell, and Prince walks over to the piano and starts playing ‘A Case of You.’ Then Joni says, ‘Oh wow! That’s really pretty. What song are you playing?’ We all yelled, ‘It’s your song!’ Prince got such a kick out of that.”

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