In 2009, Savannah, Ga., act Kylesa perfected its sludge metal style with Static Tensions. Just a year later, the band has already progressed beyond that sound with Spiral Shadow. It's the kind of record that should easily win over converts. It's the group's most accessible release to date, as it skews closer to '90s alternative à la Alice in Chains while still adding more psychedelic elements and even, on occasion, revisiting Static Tensions' assault. Yet it's these very same characteristics that might alienate fans, especially during the record's second half. Given time, though, Spiral Shadow reveals itself to be every bit as good as Static Tensions, just for different reasons.

When listening to opener "Tired Climb" for the first time, however, any differences between the two albums will seem negligible. Everything Kylesa does well is on display--twin drum kits bash and crash through dissonant guitars and vocals that can jump from dreamlike (Laura Pleasants) to gruff (Philip Cope) in an instant. It's obvious why this is the first track--the song rocks. But stylistically, it's a key move, an opening salvo that will satisfy metalheads before gradually feeding them new ideas.

Bassist Corey Barhorst lays down a thick, fuzzy bassline on "Cheating Synergy" before adding a haunting keyboard line that perfectly complements the song's guitar harmonics. "Drop Out" retreats a little, just in case people can't handle the group's newfound sense of atmosphere, by blowing through another percussive punch. "Crowded Road" brings back a nice sludgy riff. Then the record tries something else to hook in listeners--a legitimately catchy song. "Don't Look Back" sounds like Kylesa alright, but it features an infectious hook so simplistic in design it's a wonder no one else thought it up first. The chorus is "Keep moving / Don't look back," which is right up there with such obvious punk statements as "don't trust the government" and "I am a rude person," but it works. The guitars are still sludgy, but the solo that cuts through the haze is triumphant. Fifteen years ago, this song would have dominated 120 Minutes.

The back half gives itself over to psychedelia. "Distance Closing In" is hazy, even for sludge metal, with the vox buried deeper in the mix and the guitars creating a cloud over the rest of the instruments. "To Forget" is just trippy. It all culminates in the five-minute title track, a retro-leaning piece of noodling guitars and tribal drums. There are still two more songs after it, but they're just victory laps. "Spiral Shadow" is too epic.

Depending on what track is playing, Spiral Shadow manages to be both Kylesa's most mainstream and experimental record, and a reward and a challenge to fans. Either way, Kylesa is in charge.