In Welsh folklore, Cwn Annwn is an otherworldly group of hounds whose presence portends death.

In the Twin Cities, Cwn Annwn is a melodic metal band that rehearses underground at Kooler Sound in St. Paul.

Yes, that’s a fairly melodramatic way to describe a basement, but the gritty fluorescence of the halls in the facility felt separate from the outside world above. The growled lyrics and harsh electric guitar of 20 or so other bands flooded the hallways that make up a grid of practice rooms.

Drummer Jake Stone opened the door to his band’s rehearsal space, which was no larger than a modest bedroom.

“You can stand wherever you want,” he said. “Just try not to get hit by a drum stick.”

The quintet shuffled into the room and strapped on their instruments of choice — thick-gauged seven-string guitars, a menacing bass and a classic black microphone belonging to vocalist Julie Stelmaszewski.

Stelmaszewski was quiet as she clutched the microphone in her hand, looking at empty bottles of Mountain Dew and webs of cables strewn across the floor. But as soon as the first song from Cwn Annwn’s new record, “Metamorphosis,” kicked in, she came alive. Her small frame took a powerful stance facing the PA system, and she belted out a straight-tone suitable for Iron Maiden. Paired with the palm-muted attack of Harry Rostovtsev’s guitars and sweeping scales of Neil James, Cwn Annwn sounded like a marriage of 1980s prog-metal and Rush.

Formed in 1997 by James and Rostovtsev, Cwn Annwn was born out of a passion for metal, along with a desire for an outlet to express pent-up emotions.

“If I’m being honest,” bassist and backing vocalist Mike Strohkirch said, “I learned how to scream from yelling at my parents. I don’t really know how my voice has kept up for so long.”

Since the band got together fresh out of high school, Cwn Annwn experienced a series of lineup changes in the early 2000s before settling on their current roster in 2007. James said they’re a tightly knit unit, citing their ability to argue well and their willingness to accept each other’s quirks as an advantage.

“It helps that the music we play is the most fun to play, in my opinion,” he said. “It’s athletic and powerful, and we strive to make all of it as memorable as we can.”

Rostovtsev said the metal music scene can get infatuated with who plays heaviest and fastest, but Cwn Annwn isn’t preoccupied with that.

On their newest record, “Metamorphosis,” the band goes for a less-narrative connection with their audience than their last effort, “The Alpha and the Omega.”

“‘The Alpha and the Omega’ is a concept album, which was one of the most fulfilling things to write lyrics for,” James said. “It was also something I’ll never do again. It’s so difficult to get the flow to work perfectly.”

“Metamorphosis” sets high-concept aside and acts as a collection of songs that are open-ended, though it maintains Cwn Annwn’s expansive distorted assault. It succeeds with tracks like “Stay Forever,” a gentler song that showcases Stelmaszewski’s glittering vocals with a deceptively intricate drumming pattern that proves Stone has nuance along with driving blast beats.

“We aren’t the sort of metal band that just stares at their guitars when they play,” James said. “We want to have a connection with the audience and let everyone shine.”

“That is really important,” Stelmaszewski said, quickly following James’ comment. “If the audience can understand the vocals, which is sometimes impossible at these shows, I do my best to tell a story.”

What: Cwn Annwn with Gabriel & the Apocalypse and Hate Beast
When: 9 p.m. Friday
Where: The Triple Rock Social Club, 629 Cedar Ave., Minneapolis
Cost: $8
Ages: 18+