Philadelphia’s Hermit Thrushes are happy to confound and challenge. Their latest album, Potsherd Gold Meadow, is part noise collage, part field recording, part deconstructed folk music, part experimental-jazz-weird rock potpourri. If you hear a little bit of unconventional, hard-to-categorize groups like God Is My Co-Pilot, Marmoset and U.S. Maple in what they do, you are not alone. Potsherd Gold Meadow is forever falling apart, strange sketches, ideas expanding, but it doesn’t feel unfinished. Its refusal of polish, refusal to capitulate, is its ethos.