Sometimes the drone is the text, and sometimes it’s the subtext. It’s the text when it’s the overarching sound. It’s the subtext when it fills out some other overarching construct. The latter is the case with “Emporium Drone 005” by Cousin Silas. In it, the contour of a lush melody — halfway between neo-classical and popular song — played at a sedate pace is treated as if it were a silhouette, a shape left to be filled by an assembly of Silas’ drones. The overall effect is that of an orchestra heard through a thick, velvet scrim.