It's not immediately apparent what makes Silkworm more than the sum of its overworked parts. On the surface, they're like many other alt-rock bands who've relocated to Chicago (in their case via Missoula, Montana and Seattle), propelled by a slow, machine-like rhythm section, singers who strain for every note wrapped abrasively in a cold economical 'recording' that could only be from one Steve Albini. But their herniated growls have given them more staying power than their many contemporaries, and 17 years and nine albums to their name grant them a legitimacy that's mighty important when emoting in the 'emo' scene. These seven tracks in little over half an hour cheers to brevity in this age of the bloated 70-minute album don't do anything extraordinary. They're plodding rockers sparked by grinding guitars, touches of keyboards and lyrics that skirt as many issues as they engage. Within this elusive formula, however, hides the real fury that makes a simple, worn statement such as "'Don't Look Back'" sound like a true call to arms. It's this ability to empower the mundane that make another 17 years all the more likely.