Imagine you’re at home, settling in with coffee and a book, and you hear the rain trickling against the window. It grows to something louder, a steady pattering. The sound of it makes you feel relaxed, a little calmer. What about the sound makes people feel calm? When you’re at the opera, you hear the orchestra pulsing from below the stage, the choir roaring on stage and the soprano delivering a beautiful song from centre stage that fills the hall. It sends shivers down your spine—but what in your brain is being triggered to make you feel this?