Released a week before the world changed, System of a Down’s second screed took a snapshot of American exceptionalism at the turn of the millennium: the prison-industrial complex, drug addiction, hidden CIA-funded wars. It sounded like nothing else at the time — or even now. Nominally nu-metal but more of a hypercharged distillation of Mr. Bungle’s bizarro-thrash, Serj Tankian’s schizophrenic screeching and Daron Malakian’s playful mind-bending prog shred immediately set them apart from the Limp Bizkits of the world. The dazzling “Chop Suey” and “Aerials” come very close to absolving KoRn’s sins and making baggy-pants metal worth it.