Scar Symmetry's brand of melodic death metal is as devastating, technical, and complex as the group's name implies, but Jonas Kjellgren is a man of straightforward tastes and views. Reached aboard his tour bus in Springfield, Massachusetts, the 29-year-old guitarist doesn't hesitate when asked to identify the most disturbing thing he's witnessed during his Swedish quintet's current 24-date North American tour: "I've seen guys who weigh 300 or 400 pounds, riding little electric carts in Wal-Mart and buying more shit, more grease, more sugar. That's insane! They should walk. The store should not be allowed to sell these guys any more unhealthy food."

Fans will burn off plenty of calories while headbanging to Scar Symmetry's music, either live or on CD. The band's 13-track sophomore outing, 2006's Pitch Black Progress, merges influences that go beyond the traditional melodic-death-metal formula of screaming plus Iron Maiden–style guitar harmonies. Opening with soothing keyboards before exploding into an uptempo onslaught, the album's first song, "The Illusionist", encapsulates the appeal of Scar Symmetry. Vocalist Christian Älvestam alternates between gargantuan death grunts and clean '80s AOR–style singing. Kjellgren and fellow axeman Per Nilsson crank out stomping, scything, brutally efficient rhythms, but Kjellgren's solos are more pure and tuneful, while Nilsson delivers a maniacal conflation of Allan Holdsworth and Steve Vai.

Drummer Henrik Ohlsson creates all the lyrics, and as titles like "Slaves to the Subliminal" and "Mind Machine" indicate, his overriding concern is people who submit blindly to media-driven manipulation. "Henrik's really good at writing interesting, meaningful lyrics," Kjellgren says. "Sure, usually the vocalist does the lyrics. But we like Henrik's so much, I think we'll do it like this forever."

Forever is a long time, but Kjellgren is making the most of what's available. In 2004, the Avesta, Sweden, native ditched his gig as the thrash-death vocalist of Carnal Forge in order to focus on playing guitar, but he left on such good terms that his former bandmates asked him to mix their latest album, Testify for My Victims, at his Black Lounge studio. "And I like the way their new music has come out 10 times better than when I was singing," he cheerfully admits.

Kjellgren, whose uncle and grandfather also pursued professional music careers, is booked solid at the studio this year, fine-tuning CDs by Steel Attack, the Absence, and Machinery. As long as he can feed himself and achieve his goal of "making the coolest music possible", he's happy.

"We want to look back in 10 years or 20 or 30 and say, 'That was a really good album,'" he says of his aspirations with Scar Symmetry. "I guess that's every musician's dream."

Scar Symmetry plays the Croatian Cultural Centre on Monday (April 9).