Lets get this out of the way: Pelican is a heavy metal band without a singer.

This has prompted journalists to create clever labels like “instrumetal” to describe them–and while such words aptly acknowledge broad themes in the music, they overlook the unique and defining characteristics of this band.

Pelican does subscribe to the high-decibel, aggressive performance ethos of the heavy metal canon, but the band members also concern themselves with structural concepts atypical to much contemporary music in general–like orchestral composition. The band’s two lead guitarists (Laurent Lebec and Trevor de Brauw) employ varied harmonic techniques, while the group’s non-standard song structure yields 1-minute tracks that are astoundingly intricate tapestries of sound.

But in the beginning Pelican was just a grindcore band, only it went by the name of Tusk. Lebec, de Brauw and drummer Larry Herweg met in 1996, while Lebec was an undergrad at Northwestern University in Evanston, Illinois. All three were involved in the punk and hardcore scene and had similar influences, so it wasn’t long before Tusk was born. Independently, Lebec began writing acoustic songs of a very different nature, and although his bandmates showed enthusiasm for the new music, it didn’t really fit with Tusk’s style. So they formed a new band, Pelican, and invited Herweg’s brother Bryan to join them as their bassist.

“At first I think that there was definitely an affinity with Isis and bands that are heavier but slower and have a more plodding nature to them,” Lebec says. “I think that as time went by we ended up going further back in time for the inspiration that’s moving us now.”

Now, with the release of their second full-length, The Fire in Our Throats Will Beckon the Thaw (Hydra Head)–which is not as categorically heavy as their 2003 debut, Australasia–Pelican is steadily accruing a base of fans from across music genres.

“We noticed right away, even playing in Chicago, that a really wide variety of people were coming–it wasn’t all metal heads,” says Lebec, happy that Pelican has avoided being pigeonholed. “Now that people have so many options for downloading music you’re really aware, as a band, that how you get categorized really has a repercussion on how your music will be interpreted by people who aren’t familiar with it. Especially as an instrumental band.”