For decades, blues, soul and gospel singer-guitarist Robert Finley stayed in north Louisiana. A resident of the small town of Bernice, he backed gospel quartets, played music for local TV programs and performed solo at a restaurant.

In 2016, Finley released his debut album, Age Don’t Mean a Thing. In August, Z2 Comics released New Orleans writer Gabe Soria’s graphic novel, Murder Ballads. Finley sings the novel’s five-song soundtrack, a companion project produced by Soria’s f...