Before producers could fake it, reverb meant finding a real physical space and praying it sounded right — and some of the most emotionally devastating sounds in recorded music came from stairwells, tiled bathrooms, and a concrete echo chamber nobody was supposed to use. This episode traces how the obsessive hunt for the perfect reverb shaped everything from Phil Spector's Wall of Sound to the gated drum thunder of the 1980s to the cavernous loneliness of modern sad-boy bedroom pop. It turns out the size of a room can break your heart.