Where to begin? I should start with the ornamental comb, like three white gleaming stakes from some Gnostic purification ritual, holding a jet-black stack of hair atop the fiery head of Polly Jean Harvey. She's never wanted for making an impression. Wrapped in white, backed by a hard avant-garde blues band (the warm up music was a Howlin Wolf mix) that looked like they'd just gotten away clean from an S & L hold up circa 1945, PJ approached her "showcase" (a ridiculous concept in her case) l