Jack White covers Free with Chris Robinson; Billie Joe Armstrong rocks Mott the Hoople with Bruce Dickinson

Thursday night was a night of all-star rock collaborations.

Jack White’s concert in Chicago featured a surprise appearance from Black Crowes frontman Chris Robinson. The “She Talks to Angels” singer joined the “Seven Nation Army” rocker for a rendition of the Free song “I’m a Mover.” Robinson sang lead vocals while White shredded on guitar.

You can check out a video of the performance now via White’s Instagram.

Meanwhile, over in San Diego, Green Day frontman Billie Joe Armstrong was playing a gig with his side project, The Coverups, when Iron Maiden frontman Bruce Dickinson showed up unannounced.

Dickinson joined Armstrong and The Coverups to cover the song “All the Young Dudes,” originally written by David Bowie and recorded by Mott the Hoople. The “Run to the Hills” vocalist previously put his spin on the “All the Young Dudes” for 1990 solo album, Tattooed Millionaire.