Cortney Tidwell needs little introduction around these parts. As a solo artist, she makes soaring, instrumentally rich post-rock anthems while backed by some of the best musicians in the local rock scene. As one-half of KORT’s frontpersons — the other half, of course, being Lambchop’s Kurt Wagner — she performs beautiful renditions of country classics from the Chart Records catalog with heartrending sincerity. And as Feverqueen, Tidwell — sometimes accompanied by another player or two, sometimes completely solo — performs amorphous, experimental sets that are heavy on improvisation. “Improvisation is my favorite form,” says Tidwell. “If I could improvise every show, I’d be in heaven.” Perhaps the most compelling Feverqueen tunes are the ones in which Tidwell plays both Omnichord and drums at the same time, crafting atmospheric compositions that land somewhere psychedelic pop and hip-hop. Also performing are William Tyler — KORT’s lead guitarist, who’s responsible for the picking and shredding found on records from Lambchop, Silver Jews and more — and experimental ambient duo 84001. And if you’re into feeling like you’re floating through the stratosphere on your way to spiritual enlightenment while accompanied by formless, serene, alien dirges, you’ll probably like 84001. Posttaste and Anonymous open.