At a Lollapalooza after show in Chicago, Foos hit the stage with special guest, Perry Farrell.
Perry is best known as Jane's Addiction's vocalist, but is also a Lollapalooza founder - go figure.
Perry joined the band for a cover of the Jane's Addiction tune 'Mountain Song', and it sounded pretty mint.
Foo Fighters and Jane's Addiction cover 'Mountain Song'
Music