For “The Ghost,” the sixth track on their album Piramida, Denmark’s Efterklang tapped Spanish filmmaker Victor Carrey to create a puzzling video filled with individual accounts of death but together makes a unified story about a magical ancient necklace. They met the director at a film festival in Spain a month before they camped out in the desolate Norwegian town of Spitsbergen, where they explored for nine days collecting over 1,000 sounds that would help comprise the outstanding album.