The Frontal Cortex

Music, Patterns, Sine-Waves

Sine-Wave speech is a wonderful example of the importance of patterns when it comes to our sense of sound. When people first hear a sentence that’s been artificially degraded, the sentence sounds like a sequence of “simultaneous whistles, or science fiction sounds.” However, when people are first played the undistorted sentence – they’ve been given the perceptual pattern in advance – they are able to easily interpret the garbled noises. Click here for an elegant example of the phenomenon.

In my book, Proust Was A Neuroscientist, I use this search for patterns – the brain is a pattern-making machine – to explain the allure of music:

It is this psychological instinct–this desperate neuronal search for a pattern, any pattern–that is the source of music. When we listen to a symphony, we hear a noise in motion, each note blurring into the next. The sound seems continuous. Of course, the physical reality is that each sound wave is really a separate thing, as discrete as the notes written in the score. But this isn’t the way we experience the music. We continually abstract on our own inputs, inventing patterns in order to keep pace with the onrush of noise. And once our brain finds a pattern, we immediately start to make predictions, imagining what notes will come next. We project our imaginary order into the future, transposing the melody we have just heard into the melody we expect. By listening for patterns, by interpreting every note in terms of our expectations, we turn the scraps of sound into the ebb and flow of a symphony.

To demonstrate this psychological principle, the musicologist Leonard Meyer, in his classic book Emotion and Meaning in Music (1956), analyzed the 5th movement of Beethoven’s String Quartet in C-sharp minor, Op. 131. Meyer wanted to show how music is defined by its flirtation with–but not submission to–our expectations of order. He 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. Beethoven saves that chord for the end.

In that sense, Beethoven is using the same trick as sine-wave speech. By giving us a melodic pattern at the beginning of the symphony, he hands our brain an interpretative key, allowing us to make sense of all the ensuing notes.


  1. #1 Ben K.
    December 10, 2008

    Have you had a chance to read This Is Your Brain On Music? It’s a full neurological workup on the relationship between the brain and music.

  2. #2 6EQUJ5
    December 10, 2008

    Once when I was falling asleep, just beginning to slip into a dream, a sudden loud noise startled me fully awake. I had no idea what it was or where it was from, but in about second I wondered if it was a gunshot.

    Then came another loud noise, which I recognized as a gunshot coming from the street, fired from a short-barreled handgun, not a .22, but a small-caliber centerfire, either a .25 or .32. Now that I was thinking ‘gunshot’ the sounds were simple for my brain to process.

    I called the PD. The dispatcher assured me it must have been a car backfiring.

    In the morning, out on the street where I thought the shots came from were two empty .25 ACP cartridges.

  3. #3 Luci
    December 10, 2008

    By the time we get to ‘he was sitting at his desk at the office’, the sine speech indeed has become easier to hear without a key.
    The sine clips reminded me of some sound puzzles in games like Rhem 3, Alida and Riven. Players have to remember patterns to use later to provide solutions. Sound puzzles can be tricky as there isn’t an easy way to make a sketch of a path or an artifact as there are with visual puzzles.

    As to music, I’m waiting for your joint interview with Alex Ross and Oliver Sacks.

  4. #4 Neuroskeptic
    December 10, 2008

    I discuss another real-life example (a “terrorist doll”!) in this post.

  5. #5 Rob
    December 11, 2008

    This is interesting. I agree with those who say music is simply the non-wordage rhetoric of speech with lots of complex organization. Anyway, just so you know, a string quartet is not part of the symphonic genre of music, it is simply a part of the string quartet genre. String quartet music is written for only four musicians, a symphony is written for 50 to 300 or more musicians. Beethoven wrote a total of 9 Symphonies and 17 string quartets in his lifetime.

  6. #6 Barry Katz
    December 13, 2008

    This is a clear explanation of one of the principle allures of music – setting up expectations and then fulfilling them in unexpected ways. (This could serve equally well as a definition of humor). In the scherzo of Beethoven’s third sympnony, the Eroica, the composer preents a syncopated, eight note descending theme and then repeats it three times during the course of the movement – each time preceded by the same intorductory material. In effect, Beethoven is teaching us this musical figure, and teaching us to expect it, in an almost pavlovian manner, each time we hear the set-up. But the fourth time the set-up rolls around, he gives us the same eight powerful notes, but this time played fortissimo, with equal note values – in other words, not syncopated. This foiling of expectations is enough to knock you off your chair.

    Setting up expectations and then fulfilling them in a manner totally unexpected, but one that also feels completely inevitable, is one of the hallmarks of great music.

  7. #7 chat
    December 23, 2008