Led by growling guitarist Warren Haynes, this brawny Southern blues-rock quartet have political discontent on their mind throughout these powerfully performed tunes. "Stone Cold Rage" epitomizes the Mule's tasty hybrid of hard riffs and thoughtful musicianship, a virtuosic kick that crests throughout the jazz-funk title track. And "Traveling Tune" celebrates the jam-band nation—in which Haynes flourishes—with elegant nods to The Grateful Dead and Allman Brothers Band.