In the midst of St. Patrick’s Day insanity in the French Quarter, there was a once-in-a-lifetime show featuring some of the very best bands making heavy, crushing music. The atmospheric, spacey sludge of New Orleans’ own Space Cadaver. The suffocating doom from Iowa’s Aseethe. Canada’s angry queer gloom cult, Vile Creature. Local psychedelic stoner metal from Mars. Impeccable double drums and a Shellac cover from Thou and The Body. While SXSW was in full swing next door in Texas, the best showcase of metal took place just two blocks from Bourbon…