Novoselic joined Foo Fighters onstage for live rendition of Vaselines' 'Incesticide' cut
Plus, Queens' Roger Taylor joined Taylor Hawkins–fronted cover band Chevy Metal for "Under Pressure"
"I didn't like my voice, I didn't think I was a songwriter," says Foo Fighters frontman
Surprise collaboration took place at Italy's Firenze Rocks festival
Dave Grohl enlists ringer at venue where he broke leg three years prior
Dave Grohl and Co. share rehearsal footage of inventive "Jump"/"Imagine" merger
Foo Fighters mainman threw down with Axl and Co. in Oklahoma
Chief Foo Fighter hits it off with Atlanta band's redoubtable rhythm section