Pelt follows musical mavericks like Harry Partch and Henry Flynt in combining Eastern influences and North American folk sounds to make visceral, challenging art music. They didn’t start out in that direction: the band’s earliest singles were middling indie rock derivative of Sonic Youth. But by the time they recorded their first album, Brown Cyclopaedia (VHF), ten years ago, Mike Gangloff, Jack Rose, and Pat Best had channeled their energies into breaking down the boundaries between noisy rock and free noise. Inspired by their southwestern Virginia surroundings and a stack of old world-music LPs from the pioneering Nonesuch Explorers series, they discarded songs in favor of improvisations that melded Appalachian mountain-music sonorities, Hindustani textures, and the blistering string sound pioneered by La Monte Young’s Theatre of Eternal Music. Their penchant for invention extends to instrumentation: Pelt’s musical armory includes a homemade cello, hurdy-gurdy, and baritone banjo. Pearls From the River (VHF), their latest album, is an uncommonly melodic excursion enriched by Rose’s increasingly splendid fingerpicking, Gangloff’s resonant banjo plucking, and Best’s keening, low-end bowing. Mikel Dimmick, who’s long been recording the band and tending its archive, recently became an active member, adding electronics to the otherwise unplugged ensemble. Gangloff also plays banjo and resonator guitar with the Black Twig Pickers, a trio whose relaxed, shambling sound probably won’t impress any bluegrass purists but whose original dance tunes and murder ballads are deeply rooted in old-time Appalachian music. Christina Madonia (formerly Carter) of Charalambides opens, followed by the MV & EE Medicine Show (Matt Valentine of Tower Recordings and his partner, Erika Elder) and Born Heller. $8. Sunday, July 18, 8 PM, Empty Bottle, 1035 N. Western; 773-276-3600 or 800-594-8499.