Why does music sometimes send a wave of goosebumps across your skin? Neurobiologists call this phenomenon frisson. It happens when music triggers a sudden surge of dopamine—the neurotransmitter tied to pleasure, reward, and motivation. Frisson is most likely to appear during moments of unpredictability: an unexpected chord change, a sudden silence before a climax, a powerful vocal entry, or a harmonic shift the brain didn’t anticipate. These surprises momentarily break the brain’s predictions, a