How do you write an 11-minute powerviolence song? How is that possible? As a genre, powerviolence is defined, at least in large part, by its brevity. Bands challenge themselves and each other to come up with short, disorienting bursts of anxiety. A song might be 45 seconds long, and it might switch riffs and tempos three times. The whole point is to keep you on edge, off-kilter. You can’t settle into a groove. The very idea of groove is antithetical to the entire project. But the best powerviolence song that I’ve heard in a long minute is Brain Tourniquet’s “An Expression In Pain,” a berserk marathon that roils and splinters and heaves and spits for 10 minutes and 49 seconds. It moves from guttural grind to soul-shattered noise to demonic march to god knows what else, and it earns every second.