I guess I should make it clear that, contrary to the title of my talk, Kanye West isn’t really a neuroscientist. (Conveying irony via the internet isn’t easy. Although it’s still amusing to imagine him, in full rapper regalia, doing minipreps and PCR’s.) So what does Kanye have to do with the brain? Well, I use one of his songs to illuminate the basic cognitive mechanisms underlying the perception of music. I think one of the benefits of looking at art through the optic of neuroscience is that you can see all sorts of surprising connections. You can see that a rap star uses the same basic set of acoustic tricks as Igor Stravinsky, or Beethoven, or Brams. Here is how I describe the secret of music in my book:
The structure of music reflects our brain’s penchant for patterns. All tonal music (and all Western music pre-Schoenberg) begins with the establishment of a melodic pattern via the tonic triad. This pattern establishes the key that will frame the song. Our brain desperately needs this structure, as it gives us a way to organize the ensuing tumult of notes. A key or theme is stated in a mnemonic pattern, and then it is avoided, and then it returns, in a moment of consonant repose.
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 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.
I’d also like to thank everyone at the Clinton School for having me. I had a really great time.