Assembled by Metallica drummer Lars Ulrich and one-time Sounds and Kerrang! editor Geoff Barton, this two-CD set arguably constitutes the definitive historical re-cap of the most important development in the history of heavy metal, the New Wave of British Heavy Metal. Throughout the '70s, bands like Led Zeppelin, Black Sabbath, Deep Purple, Judas Priest, Motörhead, and countless others were, at different stages in their careers, saddled with the "heavy metal" label. But what this term entailed, exactly, remained sketchy at best, and it wasn't until the decade's end that any remotely acceptable definition would arise. The punk revolution that shook the U.K. in the mid-'70s had sparked a monumental do-it-yourself grass-roots movement in rock & roll, the likes of which had not been seen since the advent of Beatlesmania over a decade earlier; and, as it happened, the very next generation of would-be rock stars gravitated toward heavy metal, long present but almost always uniformly panned by critics, as the next underground springboard from which to take up the torch of discontent. Thus was spawned the New Wave of British Heavy Metal, which, like any "scene," was as much a result of the actual musicians involved as the overactive imaginations of magazine writers and their calculated need to "package" certain musical trends together for their readers' easier consumption (in the case of the N.W.O.B.H.M., said baptism is often attributed to the abovementioned Barton, incidentally). Also, as is often the case with such semi-imaginary "scenes," only a select few bands actually amount to anything in the long term, the rest generally riding their coattails for a short spell before quietly fading into rock & roll oblivion. The same is of course true for the N.W.O.B.H.M., but such was the impact of this ragged rock group collective that the period between 1979 and 1981 has now become clearly identified as heavy metal's coming-of-age process, during which most of the crude definitions for its countless sub-factions (thrash, pop, death, glam, doom, etc.) were finally outlined. So, what to expect from New Wave of British Heavy Metal '79 Revisited? Well, besides the usual cheesy liner notes from co-compilers Ulrich, and, to a lesser extent, Barton, a huge majority of these tracks fall within the Sabbath/Priest axis, stylistically speaking: from the wonderfully revealing early cuts by eventual scene survivors Iron Maiden ("Sanctuary") and Def Leppard ("Getcha Rocks Off") to the movement's tragically overlooked middle echelons (Saxon, Diamond Head, Angel Witch, Venom, Samson, Tygers of Pan Tang, etc.), to such relative unknowns as Sweet Savage, Blitzkrieg, Jaguar, Holocaust, et al. But it also contains faithful tributes, like White Spirit's Deep Purple fixation, Praying Mantis' Thin Lizzy-esque attack, Witchfinder General's Sabbath-like power chord dirge, and even girl group extraordinaire Girlschool's Motörhead derivations. And, finally, it unearths a number of long-lost treasures and off-the-beaten-path thrillers like Raven's turbo-charged "Don't Need Your Money," Witchfynde's prog-tastic "Leaving Nadir," and Trespass' sublime hard-rocker "One of these Days." Ultimately, hundreds of other equally overlooked bands (not to mention alternate song choices) could have been chosen for inclusion in this collection, but it's hard to envision a more comprehensive and lovingly conceived 30-song primer than this one to summarize such a brief, yet crucial chapter of rock history.