Watch: Foo Fighters & Guns N' Roses Play 'It's So Easy'

Foo Fighters surprised fans during their concert in Firenze Italy and invited members of Guns N' Roses on stage to perform GNR's  'It's So Easy.'

Axl Rose, Slash and Duff McKagan took the stage with the Foo Fighters as they headlined on their current Concrete and Gold Tour.  Their set included hits such as "Learn To Fly," "My Hero" and encore songs "Times Like These," "The Sky Is My Neighborhood" as well as Queen's "Under Pressure."

The band members seem to like to crash each other's sets. Last year, Foo Fighters frontman Dave Grohl performed "Paradise City" with Guns N' Roses during the bands stop in Tulsa, Oklahoma.