While Amy Oelsner has been independently releasing home-recorded music since 2004, Elastic, her second studio album, showcases a notable shift in gears. Her trademark lo-fi pop is in full effect, but here she’s also plucky, fierce, and muscular. “Lavender Night” melds stabbing, driving guitars with uneasy, minor-key bridges, while “Spill” and “Spacey Feeling” employ vocal layering and distortion to magnify her gutsy voice. But with the twinkling “David,” she doesn’t stray too far from her dream-pop roots.