Back in 1971, Paul McCartney recorded an instrumental version of his just-released album Ram. Made under the name Percy "Thrills" Thrillington, and simply titled Thrillington, the record didn't see release until six years later.

Nobody knew it was McCartney. And the thing is, he didn't want them to know and wouldn't admit that it was his work until two decades later, when he told an interviewer in 1989 that the project was indeed his.

The story behind the Thrillington album is recounted at Dangerous Minds.

Ram, which was released in May 1971 and credited to Paul and Linda McCartney, included his first post-Beatles No. 1 hit, "Uncle Albert/Admiral Halsey." A month after the album came out, McCartney went into the studio with some musicians and vintage-sounding backing singers and, serving as producer, assembled an instrumental version of Ram.

The LP was supposed to come out soon after, but the record was shelved as the McCartneys assembled their new band Wings. Fast-forward to 1977, when the album was quietly released to little fanfare.

While McCartney's illustrated face was seen on the album's back cover, there was no real indication he had anything to do with it. Dangerous Minds points out that Rolling Stone ran a story around the time of Thrillington's release hinting that maybe – just maybe – the former Beatle was behind the record's pre-rock 'n' roll take on each of Ram's 11 songs.

In 1989, during a press conference in Los Angeles, a writer asked McCartney about the album. “What a great question to end the conference!" he said. "The world needs to know! But seriously, it was me and Linda – and we kept it a secret for a long time, but now the world knows! You blew it!” McCartney also wrote the album's liner notes, under the pseudonym Clint Harrigan.

These days, Dangerous Minds notes, original pressings of the Thrillington album can sell for hundreds of dollars online. But you can also find the entire record as part of 2012's deluxe box-set reissue of Ram.

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