Ain't no folkie fest no more.

Angus Andrews, singer for the Liars, is prowling the Pitchfork main stage, shrieking over the band's fractured, stop-start rhythms. The cacophony he's raising is terrible and terrifying. His vocals -- a series of owl cries and electronically distorted yowls -- rise and fall over guitar lines played carefully just a half tone off where they should be, and the bass lurks and dodges in the lengthening shadows. This doesn't sound like a 10-year-old band. The Liars are still throwing in everything and the kitchen sink, like an underpracticed, angry Supergrass, though they've definitely ramped up the intensity of their caterwaul since the release of this year's "Sisterworld." "The devil's in Chicago at motherf---in' Pitchfork!" Andrews shouts. Then, in his lovely British accent, he politely and demurely says, "Thanks so much for having us" and preaches for a second about not throwing water bottles. I knew it was all an act.