The first time a microphone steals a scene on the set of a movie, nobody cheers. It just sits there, off camera, turning the world into a problem. The wind is suddenly a villain, airplanes are saboteurs, a squeaky shoe can ruin a take. Universal City learned this quickly. Within a few years of sound arriving, the studio had sound stages equipped and three rooftops painted with a message the whole sky could read: “Universal Pictures. Quiet.” Pilo…