If you read the title of this article and asked, “Who the hell is Kylesa,” many other readers would probably echo your sentiments.

Emerging from the swamps of Savannah, Ga., in 2001, Kylesa is a sludge band that has released some of the most interesting hard rock and metal of the 2000’s.

Now your second question should arise: “What the hell is sludge?”

Sludge can be described as a sub-genre of metal which employs heavily distorted guitars, shouting vocals, pounding tempos and a slight groove. Though this is a loose description of the band’s sound, Kylesa should absolutely not be confined to genre-labeling.

The band’s ever-evolving sound is like a repeating lab experiment yielding fascinating, fuzzy results from album to album.

Exhausting Fire begins with the track “Crusher,” which opens with a chugging metal riff and the female vocals of guitarist Laura Pleasants.

Fans of the Oakland metal trio High on Fire should delight in banging their heads to the main riff on this one.

This leads into “Inward Debate,” which features the vocal trade-off between Pleasants and guitarist Phil Cope, which is a staple of the band’s vocal delivery.

Pleasants and Cope pepper the verses with their dual vocals until the chorus, which sees Cope expanding his voice to a light shouting.

“Moving Day” slows things down even more than the previous numbers, featuring a spacey psych-rock jam with Cope’s almost-languid vocals floating through the verses.

“Shaping the Southern Sky” utilizes a bluesy hard rock riff reminiscent of another K-band, Kyuss, before airing out mid-song into another spacey landscape, then returning to a frizzy, hard rock thump.

“Falling” takes us into a weird, rippling tune layered with effects.

The tracks “Night Drive” and “Blood Moon” make extremely effective use of the dual layered vocals of Pleasants and Cope.

“Out of My Mind” maintains a steady pace through much of the song before molting into a galloping, thick-toned race towards the end of the track.

The album closer, “Paranoid,” is a take on the signature Black Sabbath banger of the same name.

Kylesa’s ultra-doomy, acid-rock cover of the track stretches out the main riff into a slow, droning, shoegaze crawl. Their version clocks in at just under five minutes, whereas the original 70’s track only reaches about three minutes.

The songs on Exhausting Fire showcase a unique aspect of the Kylesa sound: dual drumming. Kylesa’s past releases have made use of two drummers instead of one, which produces a listening experience that would have you believe the tracks are over-dubbed.

Kylesa craft experimental hard rock is full of varying influence and shifting tempos.

They are uninhibited by limitation, and their progression between each release is heard on each track. Their riffs are rich with the spirit of the Melvins, and Exhausting Fire is another exercise in the evolution of a genuine group.