Who the hell is Johnny Cash? He’s Nashville and Greenwich Village, Memphis and the holy land, a fundamentalist who in his earlier incarnation as country’s angry young man got himself banned from the Grand Ole Opry after busting out the footlights during an amphetamine-induced pique. Cash summed it up best himself in “Highwayman” when he sang the ultimate space cowboy line, “I fly a starship / Across the universe divide.” Cash’s reach, marked by some flaky moments, has indeed been vast and brilliant. The Sun recordings, including songs like “Hey Porter” and “I Walk the Line,” burn with modern power. Original guitarist Luther Perkins played like a punk rocker, and his spare, alternating-note guitar drone has remained Cash’s trademark. The man in black has never stood still, and his impulses have taken him to some odd places. The same year he talked tough for prisoners at San Quentin, he waxed esoteric in the liner notes of Bob Dylan’s Nashville Skyline, describing the Nasal One this way: “This man can rhyme the tick of time / The edge of pain / The what of sane.” Things got even stranger on “Girl From the North Country,” when these two born-again-Christians-waiting-to-happen, in an utter refusal to harmonize, warped the duet into a timeless classic. Through it all Cash has remained vital, relevant, and unique, earning inductions into both the country music and rock and roll halls of fame. Recently inked to Rick Rubin’s American label, Cash winds up another remarkable year by taking his Christmas show on the road. He doesn’t bust out the lights anymore and there won’t be any bourbon in the eggnog, but this left-wing Bible thumper still knows how to rock the house. Sunday, 4 PM, Star Plaza Theatre, 1-65 and U.S. 30, Merrillville, Indiana; 734-7266.