Don’t know anything about metal? Don’t particularly like metal, but want something a little heavier in your musical diet? Check out the roster of Hydra Head Industries, where the bands are a sure bet for satisfying your more persistent dark moods, even if they aren’t all metal-by-definition (hello, Pelican!). What is the definition, anyway? Merriam-Webster provides “energetic and highly amplified electronic rock music having a hard beat” (hoo boy, I can’t wait to see what they do with “crunk,” which got the nod for this fall’s edition), but All Music Guide reads, “of all rock and roll’s myriad forms, heavy metal is the most extreme in terms of volume, machismo, and theatricality.” Also not so accurate in 2007. So many music fans have come to trust Hydra as a quality-stamp that the label now releases, alongside bona-fide metal and math heavy-hitters ISIS and Botch, the veiled shoegaze of Jesu and the sludgy but completely indie-rockin’ Pelican. The Chicago band’s latest, City of Echoes, could be their best. It’s got all the ingredients—OK, a little bit of theatricality and a lot of volume, if not machismo—for those waking dreams a really good rock show can propel you into. With Clouds and Gargantula.