Riffing on R&B singer Ernie K-Doe’s one-time statement, Chris Rose writes in the Oxford American, “I’m almost positive that all music, at least all American music, comes from Louisiana.” The essay appears in this year’s OA Southern Music Issue, a reliably excellent source of tunes and writing. Indeed, as Dwight Garner put it in The New York Times, the CDs that accompany each annual issue “practically belong in the Smithsonian.”