For a metal band to receive notice from more mainstream music critics, it generally must be controversial or have a sound rooted in experimentation or gimmickry.

Where Kylesa falls into these, if they do at all, is up for debate, but their sixth LP, 'Ultraviolet,' doesn't find the sludge-metal five-piece pandering to a wider audience. That's clear from the opening assault that is 'Exhale.' The dueling male/female vocals at the forefront of the album will raise strong opinions from both Kylesa's supporters and detractors, but those who take the opinion that women don't belong in metal are (a) wrong (b) horribly sexist and (c) not listening.

Indeed, Laura Pleasants makes a much more significant appearance than ever before on 'Ultraviolet,' and in turn, Kylesa turns another page, becoming a more dynamic and exciting entity. Sure, Pleasants' haunting vocals on 'Unspoken' and 'Grounded' chafe with traditional metal expectations and make for something slightly different, but the goal of any good band should be to move beyond strict genre definitions and make new trails.

Also exciting on 'Ultraviolet' are some the subtleties: the echoed bass rattles from Chase Rudeseal at the end of 'We're Taking This,' the iconic tone on the Metallica-inspired guitar riff that guides 'Steady Breakdown' and the shoegaze-y wall of sound that finds Kylesa moving further than ever away from where they started -- in a great way. Highlight 'Long Gone' gathers all the tensions found on the album and pairs them with one of the more epic drum breakdowns you'll ever hear.

Kylesa aren't shy about showing off their their chops or flipping the script, and they don't seem to care about whether they're "metal" enough. What they do care about is pushing themselves, and 'Ultraviolet' is another confident step away from the pack, in metal and beyond.