Musical structure resembles the human brain's tendency to make patterns out of sound. Tonal music, like most classical music, establishes a pattern or key that will frame the song then dances around and avoids that key or theme until the end restoring order. The brain desperately desires this structure and constantly tries to recreate this order.
Before that pattern can be desired by the brain, it must play hard to get. Music only excites the brain when it makes the auditory cortex struggle to discover the order. If the pattern is too predictable, the music becomes boring. This is why classical musicians introduce the order at the beginning and are dedicated to avoiding it until the end. The longer we are denied the pattern we expect, the greater the emotional response when that order is restored. Harmony logic is the logic of hide of and seek.
As Leonard Meyer shows in his book Emotion and Meaning in Music, music is defined by its flirtation with and not submission to to expectations of order. Earlier theories of music believed that the emotions we find in music were a result of the way noise refers to real world images and experiences we have previously had. But as Meyer and contemporary neuroscientists argue, the emotions come from the unfolding events of the music itself: the patterns music invokes and then ignores.
"For the human mind, such states of doubt and confusion are abhorrent. When confronted with them, the mind attempts to resolve them into clarity and certainty," wrote Meyer. This nervous anticipation and uncertainty to create feeling. Music makes us uncomfortable and we love it.
Next week I'll get into the biology of the emotional quality of music, primarily its connection with dopamine levels.