Thrash is all about feeling. It’s about low-register riffs that hit you in the gut, high-flying solos that make you throw those devil horns in the air, and gravelly singing imbued with a sense of purpose and meaning. It’s about raging against the powers that be with everything you’ve got in you. The “Big Four” of thrash defined these traits. Once they hit the scene some 30 years ago, the earth truly shook.Technically from L.A. but more commonly associated with their adopted home of San Francisco, Metallica is the Big Four group with the widest appeal. Everyone loves Metallica—classic rockers who want to go hard; hard rockers and heavy metallers who want something precise and driving; punk rockers in search of a bigger, tougher sound. Metallica were the sum of diverse influences, a cauldron that had been slow-cooking an angry stew of punk, rock, classic heavy metal, and NWOBHM, finally overflowing and creating something new: thrash. Metallica’s first two albums were great, but they really busted out of their shell with their third: 1986s Master of Puppets, the record that sent them on a skyward path. Above all, throughout their signature work, Metallica has displayed an unparalleled energy—a spark of cohesion and crispness thats rarely matched, even to this day.Megadeth’s Dave Mustaine was actually in Metallica for their first few years, but he was asked to leave in 1983 due to substance abuse and behavioural issues. Also from L.A., Megadeth’s a little thrashier than Metallica: Compared to the formers balanced, well-tempered aggression, Megadeth is wilder and more NWOBHM-influenced—which is to say they feel closer to the satanic howls, classic-style solos, and soaring riffs of Iron Maiden. Their second release, Peace Sells… but Who’s Buying? (1986), was one of the decades best metal albums, and it remains near the top of many critics’ greatest-metal-records-ever lists. That said, Megadeth’s catalog is pretty divisive—some prefer Rust in Peace (1990), others Countdown to Extinction (1992). In any event, Megadeth have been hugely influential, especially in the burgeoning genre of extreme metal.Satanism, serial killers, crime, violence… these are Slayer’s bread and butter. And their heavy topics elicit equally heavy music. There’s no other way to put it: Slayer slays. Formed by Kerry King, Jeff Hanneman, Dave Lombardo, and Tom Araya, Slayer hit the scene in ‘83 with Show No Mercy, which was pretty well-received. Like Metallica, though, it was their third album that catapulted them into the realm of greatness. When the Rick Rubin-produced Reign in Blood dropped in ‘86, it announced Slayer as one of the most formidable voices in metal. Its unhinged riffs and hellish yawps conveyed the feeling that the music was constantly going off the rails, a quartet of possessed musicians just jamming too hard and fast to ever stop. Reign in Blood was the beginning of an incredible run that also saw South of Heaven and Seasons in the Abyss. Of the Big Four, Slayer is the most deranged—in a good way.Finally, we’ve got Anthrax, the only one of the Big Four from the east coast—New York City, to be exact. Anthrax has had something of a fluctuating lineup, but their core centers around guitarist Scott Ian, drummer Charlie Benante, bassist Frank Bello, and vocalist Joey Belladonna (who comes and goes). Oddly enough, their third LP was their big breakout, too. Among the Living (1987) was explosive among metalheads, and dealt with decidedly nerdy stuff like Stephen King novels, Judge Dredd, John Belushi, and, quite possibly, the film Poltergeist II. Anthrax’s music is built from big riffs and thundering drums—and compared to their Big Four peers, its not nearly as Satanic!This feature is part of our Thrash 101 online course that was produced in partnership with the good rocking folks at GimmeRadio, a free 24/7 metal radio station hosted by heavy-music experts like Megadeths Dave Mustaine and Lamb of Gods Randy Blythe. Check them out here and sign up for the Thrash 101 course here.