From its genesis in the early 1980s, thrash heavy metal has obsessed over the most forbidding subject matter.

From its genesis in the early 1980s, thrash heavy metal has obsessed over the most forbidding subject matter.

Nuclear war. Famine. Religious violence. Mind control. Demonic possession. Suburban living. Overall grimness.

Fatality, a thrash squad with roots burrowed in the Great White North's metal scene, dabbles in its share of Satanism and antisocial behavior.

But unlike many — too damn many, says Fatality — working thrash bands, these boys from Toronto keep their beer-soaked tongues buried firmly in cheek.

Fatality is rolling into Johnny B's in Medford on Monday, July 25, in support of its album "Beers from the Grave."

The band just finished an East Coast tour, which cemented the belief for lead guitarist Eytan Gordon that momentum is still building for thrash metal.

"Back east, they were excited that thrash metal is gaining popularity again," Gordon said. "A lot of people who grew up listening to old bands like Megadeth come up to us at shows and tell us we remind them of that older sound."

Thrash is defined by its hyper-fast and technical guitar work and driving rhythm. It is the subgenre of heavy metal most infused with punk and hardcore sensibilities.

Fatality's founders Gordon and Spencer LaVon have been making music together since they were 12. The duo honed their skills doing covers of MTV-friendly nu-metal bands such as Korn and System of a Down.

But soon their interests veered toward a less commercial though purer form of metal.

"We started off covering the worst bands out there, but then we listened to the classic bands like Slayer, Megadeth and Iron Maiden," Gordon said. "When we started writing our own music it just became thrash. We didn't set out to be a thrash band. It just happened."

Canada is the unsung thrash-metal Mecca, giving the scene legendary bands such as Annihilator and Anvil in the '80s. Fatality hopes to join them in the pantheon someday.

Until then, they will continue to grind out shows and cut a new record after capping this West Coast tour in August.

Fatality has little use for metal bands that take themselves too seriously, Gordon said.

"We feed off the audience and want to give them a good show," Gordon said. "I hate when bands say they are so metal they can't even smile or laugh at themselves. Just because you're in a metal band doesn't mean you have to be a humorless (expletive)."

Three songs from Fatality's newest album is available at www.fatality.bandcamp.com.