Music has to Surprise Us

Jonah Lehrer summarizes some observations on the brains of people listening to music:

The experiment was more compelling. The scientists measured the brain waves of a twenty subjects while they listened to various hymns. It turned out that unexpected notes - pitches that violated the previous melodic pattern - triggered an interesting sequence of neural events and a spike in brain activity:

Our electrophysiological results showed that low-probability notes, as compared to high-probability notes, elicited a larger (i) negative ERP component at a late time period (400-450 ms), (ii) beta band (14-30 Hz) oscillation over the parietal lobe, and (iii) long-range phase synchronization between multiple brain regions.

There are two interesting takeaways from this experiment. The first is that music hijacks some very fundamental neural mechanisms. The brain is designed to learn by association: if this, then that. Music works by subtly toying with our expected associations, enticing us to make predictions about what note will come next, and then confronting us with our prediction errors. In other words, every melody manipulates the same essential mechanisms we use to make sense of reality.

The second takeaway is that music requires surprise, the dissonance of "low-probability notes". While most people think about music in terms of aesthetic beauty - we like pretty consonant pitches arranged in pretty patterns - that's exactly backwards. The point of the prettiness is to set up the surprise, to frame the deviance. (That's why the unexpected pitches triggered the most brain activity, synchronizing the activity of brain regions involved in motor movement and emotion.)