Unabashedly cerebral and sonically violent, Gang of Four recognized punk’s sociological and artistic dead ends in the wake of the Sex Pistols’ implosion. The Leeds, England, quartet — vocalist Jon King, guitarist Andy Gill, bassist Dave Allen and drummer Hugo Burnham — smashed punk into pieces by embracing funk, dub and disco, making music as radical as their politics. On their combative, compulsively dance-y 1979 debut album, Entertainment!, Gill’s fractured rhythm guitar shreds chords and roars anti-solos as Allen’s funk bass supplies melody and Burnham rocks steady. King’s rhythmic yelp deconstructs history (“Not Great Men”), war (“Guns Before Butter”), sex (“Damaged Goods”) and capitalism (nearly every track); the combination has inspired Red Hot Chili Peppers and Rage Against the Machine as well as current club rockers from the Rapture to Bloc Party. Expanded with equally combustible singles, demos and live rarities, Entertainment! once again sounds bracingly current. “Guerrilla-war struggle is a new entertainment,” King gasps as the band captures a world in collapse.