According to the article, Justin Timberlake popped by the studio where they were recording, and enjoyed what they were playing. The collaboration quickly led to a friendship between him and singer Dave Grohl.

“We’d drink whiskey in the parking lot,” Grohl says. “He was really, really cool. Then the night before his last day, he says, ‘Can I sing on your record? I don’t want to push it, but – I just want to be able to tell my friends.’ ” So the band had him add some “la la la’s” to one track.

“He nailed it,” Grohl says. “I’m telling you – the guy’s going somewhere.”

The identity of who would be on the record has been speculated about for months. Many assumed it would be Taylor Swift or Adele due to said musicians showing a lot of love for the Foos in the past, but Grohl was kind enough to nix those names immediately. When fans got word that Paul McCartney would appear on the record, many assumed that he was the big guest vocalist, but the BEATLES legend is playing drums on one of tracks.