The small Philadelphia indie label No Quarter really found a sweet spot working with acoustic musicians like Cian Nugent and Nathan Salsburg, but rolling into town to play together are its two greatest discoveries: Toronto’s Doug Paisley and Louisville’s Joan Shelley. Paisley is a folk-rock singer-guitarist who creates beautiful music with a dark, burnished finish and complements it with reedy vocals that organically move along with gently rolling grooves (imagine a more modern, uncorny Gordon Lightfoot). Last year he released his third and best album, Strong Feelings, which sports his most ambitious arrangements and most elegant melodies yet, though nothing upstages the warm grain of his voice. Case in point: his recent single with Bonnie “Prince” Billy, “Until I Find You,” which features only guitars and vocals (with one of the guitars provided by Cairo Gang’s Emmett Kelly). Bonnie “Prince” Billy also turns up to sing harmony on a few songs on Shelley’s new Over and Even, bringing a Richard & Linda Thompson feel to the track “Jenny Come In,” but really the dazzling singer-songwriter feels more commanding on her own. With contributions from Salsburg and a few others, the album is a lean affair that emphasizes Shelley’s gossamer voice and her poetic lyrics (often depicting solitude, describing inner strength, and reveling in images of nature). Paisley and Shelley are as strong and original as any singer-songwriters at work these days, and their new records set a real standard, pairing rusticity and sophistication with nonchalant grace. For this concert they’ll perform on their own as well as do some songs together.