The Foo Fighters have succeeded on gut-busting songs, where angst and irony sit alongside warrior riffs and throaty screams. While they gravitate towards this Fooest of qualities with teeth-clenching uppers "The Pretender" and "Cheer Up, Boys," they also refresh their heavy palette with a few nods to '70s-era Steely Dan and Eric Clapton. But it's their softer side here that reigns, with acoustic gems "Ballad of the Beaconsfield Miners," featuring arpeggio goddess Kaki King, and the pensive "Stranger Things Have Happened." Is there a Foos Unplugged in the future? Let's hope so.