Alice Cooper is having so much fun on tour with Mötley Crüe, he can't even keep himself away from the mic when he's supposed to have a night off.

Cooper, who's serving as the support act on the Crüe's Final Tour, made a surprise appearance during his band's pre-show party at the Hard Rock Cafe in Stockholm yesterday, chipping in for performances of “No More Mr. Nice Guy," “Be My Lover," “Lost in America” and “School’s Out," all of which you can check out via fan-shot footage above and below. The set served as a warm-up for the band's officially scheduled gig with Mötley Crüe tonight, set to take place at the city's Ericsson Globe venue.

The Hard Rock show marks the second time Cooper has arrived unannounced on a concert stage recently; on Oct. 6, he performed with the surviving original members of the Alice Cooper Band, bringing the group back together for the first time since 2011 and offering a nice publicity bump for former bassist Dennis Dunaway, who was hosting a signing of his recently published memoir at the show.

Aside from the tour, Cooper's having a very busy year. His long-awaited all-star covers project, Hollywood Vampires, was released a few weeks ago, and he also lent his voice to a brand new update on the classic tale Peter and the Wolf, which arrived in stores Nov. 13.

Watch Alice Cooper Perform 'Be My Lover'

Watch Alice Cooper Perform 'Lost in America'

Watch Alice Cooper Perform 'School's Out'

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