After recently re-examining thrash metal's "Big Four," I began to think back on a lot of the other bands that fans of the genre were listening to back in the 1980s. Metallica, Slayer, Anthrax, and Megadeth got a lot of attention, they were far from the only popular bands playing fast and aggressive metal. The decade was a golden age for that music, and there were quite a few innovative bands from the underground that never broke hugely into the mainstream, but who're worthy of attention. This is far from an exhaustive list, and some of these bands overlap into other genres of metal or punk.

Frankly, I've always thought it was silly how rigidly some fans categorize various types of metal and bands, but if anyone is upset that I mention a group as "thrash" and not "technical neo-space action metal," or whatever, well, sorry. I hope you enjoy your career meticulously filing things at a county clerk's office.

10. CELTIC FROST

The band metal pioneer Tom G. Warrior formed after he disbanded his previous band, Hellhammer (who were also great), Celtic Frost are seen today as one of the more influential extreme metal or thrash bands. Back in the '80s, they sounded relentless, and you knew a person wearing a Celtic Frost shirt was serious about his or her metal. Despite one terrible misstep when they briefly decided to try their hand at hair-metal on the Cold Lake album, the band was consistently dark and powerful. Celtic Frost is often cited as one of the earliest influences of the Black Metal scene that would appear a few years later. I once saw them play at a club in Pasadena, where Tom Warrior greeted the crowd with "Thank you, Dallas!" He's Swiss, so maybe it was a language-barrier thing.

9. POSSESSED

Formed in 1983, Possessed is considered by many to be the first death metal band, but they were grouped in with the thrash scene back in the '80s. Guttural vocals and lyrics about satanism pushed along by the guitar wizardry of a pre-Primus Larry LaLonde made Possessed's music compelling to metal fans who liked rough edges and weren't scared of the devil. This was another band that polarized listeners, but fans love them for albums like Seven Churches, Eyes of Horror and Beyond the Gates.

8. VOIVOD

I always thought that if another thrash band deserved to be added to the Big Four, it was Canada's Voivod. They never had a huge mainstream hit, although their cover of Pink Floyd's "Astronomy Domine" got some MTV exposure. Still, Voivod was unique and lots of fans dug what they did. Adopting a sci-fi angle and music that experimented in ways most other thrash bands didn't, made them more interesting and cerebral than some others. Voivod, who will be at Scout Bar May 23, still rules.

7. EXODUS

Formed in 1979, Exodus is still playing shows despite numerous lineup changes, the deaths of two members and various hiatuses over their long career. Some former members have gone on to join Metallica, Slayer and other groups. But Exodus's 1984 album Bonded By Blood is considered a very influential album in thrash circles and still sounds fresh today.

6. DEATH ANGEL

Death Angel was formed in 1982 in San Francisco by several cousins of Filipino descent. They weathered many ups and downs, but released The Ultra-Violence and Frolic Through the Park in the late '80s. Both records were popular with thrash metal audiences and still hold up today.

5. OVERKILL

Overkill is like the Energizer Bunny of thrash — they just keep going, and going. Founded in 1980 in New Jersey, Overkill was relatively popular throughout the '80s and seemed to constantly be on tour with bands I liked. I was never a big fan, but lots of people were and Overkill seemed to be one of the more commercially successful thrash bands of the time. Every time I think of Overkill I picture their leering blond singer Bobby "Blitz" Ellsworth's weird face for some reason, and that's not something I enjoy.

4. SEPULTURA

This iconic Brazilian band experimented with many different musical styles and really came into prominence throughout the '90s, but '80s albums like Morbid Visions, Schizophrenia and Beneath the Remains made them popular with thrash-metal fans who liked darker bands. Though Sepultura were considered by most people to be death metal rather than thrash, there was still plenty of cross pollination between those scenes, and the band's horror-show sounds was great soundtrack music for all sorts of activities meeker metal fans avoided.

3. RIGOR MORTIS

Founded in the Dallas area in 1983, Rigor Mortis were major players in creating the underground metal scene in Texas. Released in 1988, their self-titled album is a classic and should be in every thrash fan's music collection. Unfortunately, founding member and guitarist Mike Scaccia died onstage from a heart attack in December 2012, but his contributions to heavy music are considerable, and won't be forgotten.

2. SUICIDAL TENDENCIES

It seemed like everyone who liked aggressive music by the mid to late '80s was listening to Suicidal Tendencies, who rose out of the Southern California hardcore scene. The crossover from punk to thrash-metal was obvious and rarely as well-realized as in this band. Heavy, fast and tight, Suicidal Tendencies were an amazing band to catch live and would be heard almost anywhere punks or headbangers hung out back then.

1. KREATOR

This German thrash band roared through the '80s, finding lots of fans through albums like Endless Pain. Fast and riff-heavy, Kreator had a loyal following and still does. They were definitely an underground band back then and their frantic-sounding guitars and gut-punch vocals were thrash at its thrashiest best.

