Perry revealed last year that he had recorded with McCartney as part of a secret project and now he has provided more details in an interview with Rolling Stone, explaining that the collaboration is part of the cover album being made by the new supergroup led by Alice Cooper.

The Aerosmith guitarist says that they worked with McCartney on a cover of Badfinger's "Come and Get It," which the Beatles legend wrote and produced for the group in the late 1960s, with McCartney and Cooper sharing the lead vocal duties on the track.

McCartney "knew all the chords, the lyrics, everything," says Perry. "He didn't have any cheat sheets. It was like he'd been playing it his whole life." He also explained what it was like to be in the studio with McCartney, "[We] were standing there and looking at each other and I tell you -- if there's any ego-lever in a room, it's Paul. It doesn't matter who you are or what you've done. If Paul's in the room, he's there. It was hard to focus on playing."

The song was recorded for the album project that will pay tribute to the original Hollywood Vampires, which was a group of rock stars that gathered together at the Rainbow Bar and Grill on the Sunset Strip in Hollywood during the 1970s.