Dave Grohl of Foo Fighters recently sat down with Rolling Stone, he mentions that Justin Timberlake sings on the band’s upcoming album:

Then there was the day Justin Timberlake dropped by. He listened to what the Foos were doing and liked what he heard, and pretty soon he and Grohl were hanging out regularly. “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.”