The experiments revealed the songs caused the amygdala, hippocampus, and auditory cortex—which help us process emotions, learn and gain memories memory, and process sounds, respectively—to light up. Meanwhile, the nucleus accumbens—which has previously been linked to rewards and deriving pleasure from music—activated when the listeners encountered uncertainty in the songs.

This led the researchers to conclude we enjoy songs when we anticipate a certain chord but are hit by another, or when we aren’t sure what will come next but are given a predictable chord.

“Music may therefore elicit pleasure by encouraging the listener to continuously generate and resolve expectations as the piece unfolds in time,” the authors wrote.