She was possessed by the spirit of a devilish Appalachian woman, and she is here with her motley trio of Victorian psychopaths to rock your world with a head-trip blend of heavyweight guitar theatrics, a shriek of down-home fiddle, and Granny’s own musty roar. She doesn’t pretend to be anything but an old woman who’s somehow fronting a rock band — armed with a bun of ivory hair, a gothic parlor shawl and a silver-tipped cane. So it’s an interesting experience, says Granny, when her project, Granny 4 Barrel, hits a venue filled with people who aren’t sure what they’re getting into. There’s nothing quite like greeting a bulwark of suspicious metalheads with some southern hospitality.