Back in the 80s, the Bay Area was instrumental in spawning thrash metal, the little musical movement that bestowed Metallica upon the world. Here's an old-school metal primer featuring some of the most influential thrash bands of all time.

1. Exodus, "Bonded By Blood"

From their debut 1985 album of the same name, this track is one of the handful to feature early vocalist Paul Baloff at the mic–a far cry from the later screams of Rob Dukes and Steve Souza (who also played in Testament). Aside from having one of the most over-the-top, brutal sounds of the original Bay Area thrash bands, it also boasts Kirk Hammett (of Metallica) as one of their founding guitarists.

2. Testament, "C.O.T.L.O.D."

This is from the Berkeley band's first album Legacy (it was actually almost their band name), which dropped in 1987 and gained them instant fame and a slot opening for Anthrax on tour. The album is a ferocious whirlwind of aggressive guitars and blast beats–on this song in particular the group vocals are enough to terrify small children.

3. Metallica, "Whiplash"

Though Metallica formed and eventually moved back to L.A., they did call the Bay Area home for a minute, when their best bassist (in my opinion) Cliff Burton, a native of Castro Valley, insisted on moving the band to El Cerrito. "Whiplash" is from 1983 Kill 'Em All, the band's studio debut which was recorded just after Dave Mustaine of Megadeth was kicked out. It's one of the earliest and most influential thrash albums ever recorded.

4. Death Angel, "The Ultra-Violence"

This Concord band released their debut of the same name in 1987, when all the members were under 20 years old. In fact, their drummer, Andy Galeon, was only 14 when it came out. This all-instrumental track showcases the jaw-dropping musicianship of these youngsters, which makes me think that if they'd debuted today, the media would flip out over their enormous talent.

5.Sacrilege BC, "Crucified"

A lesser-known and criminally underrated Bay Area thrash band (the "BC" in their moniker stands for "Berkeley, CA,") they formed in 1985 and quickly released their debut Party With God. Their sound is much more primal and punk than their polished counterparts like Metallica, their songs short and full of unbridled rage and energy.