A music festival put together by the City of New Albany, 91.9 WFPK and Houndmouth, the second Boomtown Ball features a solid — and free — lineup that runs through most of the day on Sunday. Energetic oddball Langhorne Slim, who is headlining, twists and updates roots music in interesting directions. Rounding out the lineup is the Nashville-based The Apache Relay, who mix dreary, hushed folk with pop-rock sensibilities; The Features, who bring psychedelic components to smooth rock n roll; as well as Big Big, Jalin Roze, Lazy Sunday and Lydia Burrell & The Hart Strings.