On record, Courtney Barnett can be sharp and funny and raw, but she always seems to keep at least half a foot in singer-songwriter tradition. Live, she’s something else. She’s a great punk rock bandleader, the star of an absolutely raging power trio that thrashes with the sort of early-’90s authority that would’ve made them right at home on the Sub Pop roster in ’91. She just attacks, hair and guitar flying in every direction, belting out these enormous and fearsome hooks. She’s a hero.