PJ Harvey ‘s last album found her singing about a fictionalized version of her home country. For her next project, she’s headed as far there as humanly (or inhumanly) possible. On her somber new single, “Voyager,” she imagines what the voice of the Voyager 2 , a space probe NASA launched in 1977, would say. “Force fields, high winds, cold moons, bright rings, hear my signal, will you follow?” she sings, her voice sounding spectral with glitches. “Look back at us as a speck of dirt.” Keyboards