D.R.I - Dirty Rotten LP 12"
In the turbulence of the onset of the 1980s, a social paranoia and increasing media blitz put the underground on the defensive, allowing the most extreme elements to cross over at key nodal points of intellectual activity. D.R.I. was, alongside Discharge, perhaps the most important of these unions in that by finding a way to put heavy metal riffs into hardcore punk song structures, D.R.I. found a basis for all metal to follow.
Structural metal riffing, in the heavy metal context previous to this time, had focused on Judas Priest-style logical counterpoint of phrasing, but had never transcended the mostly verse-chorus song structures of heavy metal. Hardcore punk on the other hand, inspired by the raw aesthetics of early heavy metal, had taken it to the opposite extreme with simple looping song structures but mostly very undirectional riffs. As this emptiness dawned on the community, bands like Discharge and The Exploited were coming up with more metally riffs, but still sounded like punk bands. Crossover, and the advent of the "thrash" genre with D.R.I.'s "Dirty Rotten LP," changed all of that.