In our vampire-obsessed culture, a few Twilight followers could conceivably graduate from Edward Cullen to Dax Riggs. The Texas-based singer-songwriter’s second solo album plops Sun Studios into the middle of Transylvania, with Riggs as a pensive, late-night Elvis. He references hell, Satan, witches, gallows, and other morbid tokens, in a stately croon. Then he kicks the “gravedirt” off his “blue suede shoes” and covers “Heartbreak Hotel” as a sepulchral dirge. But getting so lonely he could die should not be a problem for someone as pointedly undead as Riggs.