Hailed by AllMusic.com's Eduardo Rivadavia as "the most important development in the history of heavy metal, the NWOBHM was a short-lived explosion of young British metal acts who helped make metal faster and edgier by incorporating the influence of punk rock, while retaining the instrumental complexity and high-pitched vocals that became a metal trademark.
Notable NWOBHM's acts included Def Leppard, who later went on to multi-platinum success; Diamond Head, a key influence on Metallica among others; and Iron Maiden, one of metal's longest-running and acclaimed groups.
Thrash expanded on the template of the NWOBHM, offering fast, choppy guitar riffs with longer, more complex arrangements. Early hotbeds included California's Bay Area and New York City, though within a few years distinct regional scenes emerged worldwide.
The enormously popular Metallica was the first thrash band to make a serious commercial breakthrough, but peers like the more aggressive Slayer, the punk and hip-hop-influenced Anthrax, and German icons Kreator would make their own marks.
Glam or hair metal was the most commercially viable subgenre of the time, and also the most loathed by hardcore metalheads. Glam retained metal's volume and flashy guitar solos but incorporated pop melodies and a heavily made-up, androgynous visual image. Many formerly edgy groups like Mötley Crüe and Scorpions adopted a more accessible glam look and sound to wild success, while up-and-comers like Bon Jovi and Poison became millionaire pop idols.
Doom metal bands were attracted to the behemoth slowness of classic Black Sabbath, creating a subgenre noted for its heavy, churning guitar riffs, despondent lyrics and atmosphere of oppressive gloom. Though the subgenre never sold many records, bands such as Trouble, Saint Vitus and Witchfinder General retain a cult following.
Death metal emerged as the logical conclusion to thrash's innovations, featuring even faster guitar riffs and acrobatic drumming, shocking gore-splattered lyrics and often unintelligibly growled vocals. Though death metal would achieve surprising popularity in the early 1990s, it would be years before influential bands like Death, Autopsy and Morbid Angel escaped obscurity.