Filmed in Chicago’s beautiful brick Irish American Heritage Center during a recent tour, this four-song set begins with Fontaines D.C. singer Grian Chatten in the stacks at the center’s library, playing a button accordion and singing the mordant ballad “The Couple Across the Way” as cellist Maureen Dunne and violist Isaac Henry accompany him. An emotional touchstone on the band’s latest album, "Skinty Fia," it’s a taste of an unfinished Fontaines project: the Irish group originally planned to release a double set with half traditionally-styled tunes and half the searing, atmospheric post-punk that makes this third LP the band’s best.