Dublin Death Patrol

Metal's purest genre isn't an instrumental style, but a lyrical school: bloody tales of far-fetched, worst-case-scenario death. Its pinnacle was 1985's "Pirahna," a true ripper about deadly fish by thrash legends Exodus. Nearly 25 years later, the seeds of the genre are finally unearthed in "Unnatural Causes." The proto-thrash tale of fires and firing squads is a lost nugget from Dublin Death Patrol, a short-lived but influential metal crew from the far-flung San Francisco hinterland of Dublin.

DDP kicked around the famous Bay Area scene in the early '80s, but never recorded. The members moved on to bigger things; the 12-man all-star posse is made up of players from overlapping bands: Laaz Rockit, thrash-precursors Rampage, and marquee names Exodus and Testament. Headbangers will recognize singer Chuck Billy, singer Steve Souza, bassist Willy Lange, and bassist John Souza. They've reconvened to save their old material from the winds of time. Billy's deep road and Souza's high sneer are two of metal's most distinct voices, even if many of the mid-tempo riff-centric tunes are forgettable. But the cover of Motorhead's "Iron Fist" cements DDP's long-overdue debut. It's a mandatory lesson in metal history.