Isis singer-guitarist Aaron Turner is famously unwilling to dissect his often opaque lyrics in interviews, arguing that to do so cheapens things not only for his fans but also for himself. He doesn’t mind, however, revealing what inspires him as an artist. The answer shouldn’t shock anyone who’s heard the Los Angeles–based metal visionaries’ latest disc, Wavering Radiant. Balancing out the blast-force bombast that Isis has long excelled at are moments of almost serene, meditative gorgeousness.

Wavering Radiant’s quieter passages are transcendent enough to suggest that Turner is just as happy lost in the middle of nowhere as he is soaking up the maddening roar of modern civilization. That turns out to be exactly the case.

“I’ve just moved away from Los Angeles, up to Seattle,” the affable frontman says, on the line from a Cincinnati tour stop. “I’m living in the city right now, but the goal is to move outside of the city and live in the woods. A lot of us in the band grew up in pretty rural areas, so that’s certainly a component of who we are. We’re very social people, but there’s also an introverted tendency where we need quiet time and we need space. That is definitely reflected in the music.”

For all his reticence, Turner has let it slip that Wavering Radiant chronicles an epic conflict between worlds of beauty and the darkest of demons. Sitting more comfortably beside the collected works of Godspeed You! Black Emperor than, say, music by the latest eggheads angling for a deal with Relapse, the disc is also one of those rare records where something new is revealed with each listen. Check out the baroque-classical undertow and soft-focus organ outro in “Hall of the Dead”, the electronica mini-squalls and dream-theatre vocals in “Ghost Key”, and the deep-space bass bombs that flare up halfway though the epic post-metaller “Stone to Wake a Serpent”.

It all adds up to what critics have called the most ambitious album yet from Isis and a noticeable leap forward from 2006’s In the Absence of Truth. Turner agrees, but not without his caveats.

“I think this is probably the best record that we could have written, given the circumstances,” he says. “I always have mixed feelings during the recording process. At the point where everything is done, you can’t help but hear all the things that you would have done differently.”

That’s a tip-off that Turner and his bandmates might be their own biggest critics, something he freely admits.

“At this point, we’re five albums in and can’t repeat ourselves, mostly for our sakes,” he notes. “We need to continually challenge ourselves as players. We do a lot of work when we’re writing to make sure we’re not just recreating a song from the past in a different form.”

Which begs the question: when Turner looks back at the band’s work, is he surprised that fans haven’t been able to come to some sort of consensus as to what he’s been on about? The answer is not really, mostly because, in the world of Isis, even he’s often in the dark.

“At this point, I think we’ve got a pretty good grasp of what the new record is,” he says. “But sometimes it takes even me a while to gain a full perspective on it.”

Isis plays the Commodore Ballroom on Friday (June 19).