Husband-and-wife folk duo Laura Wortman and Kagey Parrish celebrate the recent release of their third album, Silver Lining, with their June 9 appearance at the Opera House. The duo began their careers as songwriters after their appearance and first-place win on a 2008 talent show broadcast of NPR’s “A Prairie Home Companion.” In concert the Dewdrops focus on blending sounds by singing and playing into a shared microphone. There is a high lonesome quality to the way Parrish’s voice blends with Wortman’s that is familiar, yet the mixture is unique. Their tunes and words are efficient and simple, drawing inspiration from the foothills of the Blue Ridge mountains of Virginia, where they live. Their live shows cover the ground between handmade folk songs, Appalachian fiddle tunes, and a cappella spirituals. In their own way, the duo fills up a room with sound and feeling that lingers when the show is over.