Cave In have had many musical identities since their inception in Methuen, MA, in 1995, but the one that first established them as underground heroes was the dizzying, face-ripping metal blowout now known the world over as Until Your Heart Stops.

Quicksand are as easy to classify as any band in our ever-expanding Hall of Fame: The New York quartet was post-hardcore in every sense of the term.

Death metal had never sounded so guttural and primal before Obituary’s 1989 debut, Slowly We Rot, infected record stores.

The word “metalcore” is so ingrained in modern extreme music, it seems unimaginable that there was a time when metal and hardcore were completely separate worlds.

When Darkthrone’s monumental epic, A Blaze in the Northern Sky, hit the shelves in 1991, it was an album of hesitant firsts: the first Norwegian black metal album (Mayhem’s Live in Leipzig came out earlier but with faulty distribution); the first major second-wave black metal album, globally (Czech group Master’s Hammer had released Ritual a year prior, but with less impact); the first truly blackened death metal album; and the first to chime DM’s death knell in popularity.

Of all the classic albums thus far inducted into Decibel’s Hall of Fame, none has had a greater influence on the death metal and black metal that succeeded it than Celtic Frost’s Morbid Tales.

They were the best band you never heard of. Unless you lived in the greater Boston area between 1989 and 1995, worked at Century Media, or happened to catch them on your local college radio station (or on their 1993 European tour with the Cro-Mags), Only Living Witness were virtual unknowns.

This one’s a no-brainer. Regardless of what you think about Calculating Infinity, you can’t deny that the 11 tracks on this album revolutionized extreme music and raised the bar in terms of technicality, musicianship, speed, dynamics–even visual presentation, album photography, and design.

Everyone remembers that one episode of The Osbournes some five years back where Ozzy’s ungrateful male sprog took it upon himself to use Meshuggah’s Destroy Erase Improve as a thrust and parry in the suburban war against his Beverly Hills neighbors.

After Nirvana’s Nevermind tore the “alternative rock market” a seven-figure asshole, every major label with easy access to a couple of guitar-wielding longhairs was vying to shove its swollen corporate phallus into the proverbial money-ring of brown fire.