SYSTEMSPost-rock and thrash seem to have nothing in common. The patient, atmospheric epics of bands like Mono, built on slow crescendos from whisper quiet to end-of-the-world loud, may be the polar opposite of thrash's anxious, claustrophobic churn. Yet Carrboro's Systems renders a single style from these disparate worlds, bringing post-rock's soaring, lonesome guitars and lumbering rhythms into a hard-edged stew of discordant guitar clashes and desperate, hoarse shouts. Last year's EP, Ghost Medicine, is a fantastically bleak treatise on death and loss presented in Systems' remarkable fused heaviness. With Torch Runner, Red Warlock and Monarchist. $6-$9. The Milestone.