Dubbed “two of the most compelling new voices in Americana roots music” by their hometown Chicago Sun-Times, JT Nero and Allison Russell first crossed paths when their respective bands — JT and the Clouds (from Chicago) and Vancouver’s Po’ Girl — began collaborating. In 2011, Nero’s Mountains/Forests became the first full release to showcase the harmonious energy the two singers’ voices created together.Mountains/Forests, touring frequently and gearing up for the much-anticipated debut full-length album under the Birds banner (due this summer). Birds of Chicago opens for Magnolia Mountain at MOTR Pub (1345 Main St., Over-the-Rhine). 21 and up. Free. Saturday, May 19. 10 p.m. motrpub.com.