WHEN VOCALIST CAMMIE Gilbert sings, regardless of how vulnerable the lyrics may be, it ultimately sounds like a celebration of strength. Strength, and volume, as in amplitude, for Gilbert happens to be the front woman of the progressive metal band Oceans of Slumber, one of Houston’s most popular, experimental, and critically acclaimed musical exports.

So-called “prog metal” is heavier than heavy metal: complex, visceral and really, really loud. Oceans of Slumber takes the music to new and uncharted places, and is enjoying international success both representing and exploding the genre. “We blend things people aren’t used to hearing blended in such an authentic way,” says Gilbert of the band’s unique sound, which incorporates folk, psychedelic and classical influences.

Oceans of Slumber's Cammie Gilbert

Gilbert, a 28-year-old African American woman partial to a wardrobe of both leather and lace, and usually rocking either a Mohawk or braided rows or some combination thereof, also brings a measure of female energy to a genre often stereotyped as a bastion for heavily tattooed alpha dudes. (To be fair, she has some serious ink on both arms.)

Still buzzing after a headliner performance at White Oak Music Hall’s opening weekend, Oceans of Slumber is now touring Europe in support of their latest album, Winter, named by Metal Hammer magazine and Houston Press as one of the best albums of 2016. The 34-date tour, with metal veterans Ne Obliviscaris and Enslaved also on the bill, includes stops in Berlin, Vienna and Paris. Fans well beyond Texas borders are embracing the band’s exploratory music and Gilbert’s soaring, soulful vocals.

Born in Chicago and raised in Sugar Land, Gilbert grew up in a musical household. She grew up singing hymns in choirs — her dad was a choir director — but the music she truly loved “was always much heavier … off the righteous path.” Aretha Franklin was a major inspiration. “She was boisterous and sassy. No-f***s-given, to put it not-lightly. When she came on that strong and powerful, it resonated with me.”

After singing with an improvisational band — “more artistic than musical” — and the alternative rock band Miles to Glory, Gilbert was invited by drummer Dobber Beverly to join Oceans of Slumber. The band also includes guitarists Anthony Contreras and Sean Gary, bassist Keegan Kelly and keyboardist Uaeb Yelsaeb, all “kids of the ’90s,” whose musical backgrounds encompass jazz, blues and classical. Gilbert’s rich and powerful voice gives their music its devastating emotional range, conveying subtle and varying degrees of rage, desperation and strength, sometimes within the space of a single song.

For her part, Gilbert is pleased to see a growing number of women exploring the metal genre. “I attribute that to how the internet helps a lot of minority scenes grow,” says Gilbert. “I feel it’s not as common for women to bond over music. For the few that do ... it’s now easier to find each other.” Gilbert is also happy to have helped women connect at the recent Girls Rock Camp Houston, a weeklong workshop where girls aged 8 to 18 learn how to write, perform and promote their own music. The week culminated with a concert where the campers proudly, and loudly, performed onstage at Fitzgerald’s.

Gilbert believes the success of Oceans of Slumber shows that listeners, both women and men, are indeed open to fresh, emerging styles of music. Again she references the egalitarian powers of the internet. “The radio doesn’t determine what you listen to anymore,” she says. “So you hear us, and go, ‘Metal? I didn’t know I liked metal.’”