The Frontal Cortex

The new Kanye West album is solid, although it could use a dose of ironic humor. But that's neither here nor there. What interests me about Kanye is his masterful ability to embed hooks and samples into the background of his songs. He'll literally repeat the same three second acoustic loop over and over again, until the song has this fierce forward momentum. ("The Glory" is probably the best example of this on the new album.)

And this got me thinking: why are these samples so effective? Why is my brain so riveted by an endlessly repeated shard of sound? I think the answer helps to reveal the inner workings of music.

Simply put, Kanye toys with our mental penchant for patterns. Each of his songs begins by introducing the hook/mnemonic pattern that will frame the song. Our brain desperately needs this structure, as it gives us a way to organize the ensuing tumult of notes.

But before a pattern can be desired by the brain, it must play hard to get. Music only excites us when it makes our auditory cortex struggle to uncover its order. If the music is too obvious, if its patterns are always present, it is annoyingly boring. This is why classical composers introduce the tonic note in the beginning of the song and then studiously avoid it until the end. The longer we are denied the pattern we expect, the greater the emotional release when the pattern returns, safe and sound. Our auditory cortex rejoices. It has found the order it has been looking for.

The musicologist Leonard Meyer, in his classic book Emotion and Meaning in Music, analyzed the 5th movement of Beethoven's String Quartet in C-sharp minor, Op. 131. Meyer dissected fifty measures of Beethoven's masterpiece, showing how Beethoven begins with the clear statement of a rhythmic and harmonic pattern and then, in an intricate tonal dance, carefully avoids repeating it. What Beethoven does instead is suggest variations of the pattern. He is its evasive shadow. If E major is the tonic, Beethoven will play incomplete versions of the E major chord, always careful to avoid its straight expression. He wants to preserve an element of uncertainty in his music, making our brains beg for the one chord he refuses to give us. According to Meyer, it is the suspenseful tension of music (arising out of our unfulfilled expectations) that is the source of the music's feeling.

But back to Kanye. Listen closely to his loops. They are utterly unpredictable. In "The Glory," the song begins with the sample being repeated nine times. Then the sample is abruptly interrupted. Then it's repeated another thirteen times. Then there's another brief pause. Then another ten cycle repetition. The point is that we never know when, exactly, the repetition will end. Our brain is trying to predict how many samples we will hear, but there's no way to make this prediction. Kanye has made the song into a stochastic system. As Meyer points out, all of this uncertainty is riveting.

If you'd like to know how a similar logic explains The Rite of Spring, check out this episode of Radio Lab. Or read my forthcoming book.