Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man (14 page)

Musical notes are rendered as meandering through space. Music videos are built largely from people moving, and in a manner time-locked to the music. That begins to suggest that the visual system is under the impression that music sounds like human movement. But if that’s really what the visual system thinks, then it should have more opinions than just “music sounds like movement.” It should have opinions about what
kind
of movement music sounds like, and therefore, more exactly what the movement should look like. Do our visual systems have opinions this precise? Are we picky about the visual movement that goes with music?

You
bet
we are!
That’s
choreography. It’s not OK to play a video of the
Nutcracker
ballet during Beatles music, nor is it OK to play a video of the
Nutcracker
to the music of
Nutcracker
, but with a small time lag between them. Video of human movement has to have all the right moves at the right time to be the right fit for music.

These strong opinions about what music looks like make perfect sense if music mimics human movement sounds. In real life, when people carry out complex behaviors, their visible movements are tightly choreographed with the sounds they make—because the sight and the sound arise from the
same
event. When you hear movement, you expect to
see
that same movement. Music sounds to your brain like human movement, and that’s why, when your brain hears music, it expects that any visual of it should match up with it.

We just used your brain’s visual system as an oracle to divine the meaning of music, and it answered, “People moving.” Let’s now use your brain in another oracle-like fashion. If music has been culturally selected to fit the brain, then let’s look into which pieces of music are the best fit for the brain, with the idea that these pieces may be the best representatives of what music has been culturally selected to sound like. But how can we gauge which pieces of music are the best fits? One thought is that “symptoms” of a piece of music fitting the brain really well might be that the brain would process it especially easily, remember it easily, and internally hear it easily. Are there pieces of music like this?

Yes, there are! They’re called
earworms
—those songs with a tendency to get stuck in people’s heads. These pieces of music fit the brain so well that they can sometimes become nuisances. Earworms, then, may be great representatives of the fundamental structural features that have been selected for in music. What are the common qualities of pieces of music that become earworms?

When he was an RPI graduate student, Aaron Fath got interested in this question. He was dissatisfied with the standard line that songs become earworms because they are highly repetitive.
Most
songs are highly repetitive, he reasoned. Instead, he began to notice that a large fraction of earworms have a particular dance or move that goes along with the music. Examples of songs tightly connected to a particular movement include “I’m a Little Teacup,” “Macarena,” “YMCA,” “Chicken Dance,” “If You’re Happy and You Know It,” and “Head, Shoulders, Knees and Toes.” Let’s call these pieces
movement-explicit
. He also noticed that many other earworms were songs that accompanied specific visual movements (like a commercial jingle on television) or were dance songs (even if no specific movements were associated with them).

Aaron used two existing catalogs of earworms: a top 17 list of earworms from James Kellaris of the University of Cincinnati (obtained by polling 559 students), and a list of “top annoying earworms” from an online poll at the website Keepers of Lists (one user posted 220 songs, and 80 other users voted on whether or not they were earwormy; Aaron took the 38 songs having more than 10 votes). Movement-explicit pieces accounted for 23.5 percent and 18.4 percent of these lists. To gauge whether these are unusually large percentages of movement-explicit pieces, he sampled the #8 song on the Billboard Hot 100 Chart every nine months from 1983 to the present, and among these 38 songs,
none
were of the movement-explicit variety. As a second gauge, he sampled the #1 songs for each year from 1955 through 2006 (defined by Aaron—differently than Billboard does it—as the song released in a year that was #1 on the Billboard Hot 100 for the greatest number of weeks, and thus had the most staying power). Of these 52 songs, only
one
was of the movement-explicit kind (namely, “Macarena”).

These data suggest that earworms are disproportionately movement-explicit: about one-fifth of the earworms had specific dance moves that went with them, whereas less than 2 percent of top pop songs are of this kind. Our speculation is that songs become earworms not because they are movement-explicit so much as because they are
consistent with the sounds of people moving
—movement-explicit songs just happen to be under especially strong selection pressure to be consistent with the sounds of people moving. Although only a fifth of the earworms were of the movement-explicit kind, many of the others seemed to be in the “accompaniment” or “dance” category (although we have not yet tried to operationally measure these and compare them to control data sets). An alternative possibility is that when a song becomes tightly linked to movement, it is that very association that helps make it an earworm. This would suggest that music becomes more brain-worthy when packaged together with a motor program, and this, too, would appear to point to the music-is-movement theory.

It
looks
like music may be the sounds of human movement. We asked the expert on how things look: your visual system. Like presenting a deeply encrypted code to an oracle, we asked for the visual system’s interpretation of that enigmatic thing called music, and it had a clear and resounding response: music sounds like people moving and doing things, and thus must be visually rendered as humanlike motion in sync with the musical sounds. We also queried your brain in another fashion: we asked it which songs it most revels in, which ones are so earwormalicious that the brain loves to internally sing them over and over again. And the brain answered: the more movement-explicit songs are more likely to be the earwormy ones. The brain seems to be under the impression that music sounds like people moving.

Brain and Emotion

The opinion of visual systems and the hints of earworms are interesting and motivating, but we can’t just take them at their word. In order to make a solid case that music sounds like human movement, I need to show that the music-is-movement theory can leap the four hurdles we discussed earlier: “brain,” “emotion,” “dance,” and “structure.” Let’s begin in this section with the first two.

For the “brain” hurdle, I need to say why our brain would have mechanisms for making sense of music and responding to it so eagerly and intricately. For the theory that music sounds like human movement, then, we must ask ourselves if it is plausible that we have brain mechanisms for processing the sounds of humans doing stuff. The answer is yes.
Of course
we have humans-doing-stuff auditory mechanisms! The most important animals in the life of any animal are its conspecifics (other animals of the same species), and so our brains are well equipped to communicate with and “read” our fellow humans. Face recognition is one familiar example, and color vision, with its ability to detect emotional signals on the skin, is another one (which I discussed in detail in my previous book,
The Vision Revolution
). It would be bizarre if we had no specialized auditory mechanisms for sensing the sounds of other people carrying out behaviors. Actions speak louder than words—the sounds we make when we act are often a dead giveaway to what we’re up to. And we’ve been making sounds when we move for many millions of years, plenty long enough to have evolved such mechanisms. The music-sounds-like-movement hypothesis, then, can make a highly plausible case that it satisfies the “brain” hurdle. Our brains surely
have
evolved to possess specialized mechanisms to hear what people are doing.

How about the second hurdle for a theory of music, the one labeled “emotion”? Could the mundane sounds of people moving underlie our love affair with music? As we discussed at the start of the chapter, music is evocative—it can sound joyous, aggressive, melancholy, amorous, tortured, strong, lethargic, and so on. I said then that the evocative nature of music suggests that it must be “made out of people.” Human movement
is
, obviously, made of and by people, but can human movement truly be evocative? Of course! The ability to infer emotional states from the bodily movements of others comes via several routes. First and foremost, when people carry out behaviors they move their bodies, movements that can give away what the person is doing; knowing what the person is doing can, in turn, be crucial for understanding the actor’s emotion or mood. Second, the actor’s emotional state is often cued by its side effects on behavior, such as when an exhausted person staggers. And third, some bodily movements serve as direct emotional signals, more akin to facial expressions and color signals: bodily movements can be proud, strutting, threatening, ebullient, jaunty, sulking, arrogant, inviting, and so on. Human movement can, then, certainly be evocative. And unlike evocative facial expressions and skin color signals, which are silent, our evocative bodily expressions and movements make noises. The sounds of human movement not only are “made from people,” then, but they can be truly evocative, fulfilling the “emotion” hurdle.

An example will help to clarify how the sounds of human movement can be emotionally evocative. Michael Zampi, then an undergraduate at RPI, was interested in uncovering the auditory cues for happy, sad, and angry walkers. He first noted that University of Tübingen researchers Claire L. Roether, Lars Omlor, Andrea Christensen, and Martin A. Giese had observed that happy walkers tend to lean back and have large arm and leg swings, angry walkers lean forward and have large arm and leg swings, and sad walkers tend to lean forward and have attenuated arm and leg swings.

“What,” Michael asked, “are the distinctive
sounds
for those three gaits?” He reasoned that leaning back leads to a larger gap between the sound of the heel and the sound of the toe. And, furthermore, larger arm and leg swings tend to lend greater emphasis to any sounds made by the limbs in between the footsteps (later I will refer to these sounds as “banging ganglies”). Given this, Michael could conclude that happy walkers have long heel-toe gaps and loud between-the-steps gait sounds; angry walkers have short heel-toe temporal gaps and loud between-the-steps gait sounds; and sad walkers have short heel-toe gaps and soft between-the-steps gait sounds. But are these cues sufficient to elicit the perception that a walker is happy, angry, or sad?

Michael created simple rhythms, each with three drum strikes per beat: a toe-strike on the beat, a heel strike just before the beat, and a between-the-step hit on the off-beat. Starting from a baseline audio track—an intermediate heel-toe gap and a between-the-steps sound with intermediate emphasis—Michael created versions with shorter and longer heel-toe gaps, and versions with less emphasized and more emphasized between-the-steps sounds. Listeners were told they would hear the sounds of people walking in various emotional states, and then the listeners were presented with the baseline stimulus, followed by one of the four modulations around it. They were asked to volunteer an emotion term to describe the modulated gait. As can be seen in Figure 17, subjects had a tendency to perceive the simulated walker’s emotion accurately.

Figure 17
. Each column is for one of the three tracks having the sounds modulating around the baseline to indicate the labeled emotion. The numbers show how many subjects volunteered the emotions “angry,” “happy,” “sad,” or other emotions words for each of the three tracks. One can see that the most commonly perceived emotion in each column matches the gait’s emotion.

This pilot study of Michael Zampi’s is just the barest beginning in our attempts to make sense of the emotional cues in the sounds of people moving. The hope is that by understanding these cues, we can better understand how music modulates emotion, and perhaps why genres differ in their emotional effects.

If music has been culturally selected to sound like human movement, then it is easy to see why we’d have a brain for it, and easy to see why music can be so emotionally moving. But why should music be so
motionally
moving? The music-is-movement theory has to explain why the sounds of people moving should impel other people to move. That’s the third hurdle over which we must leap: the “dance” hurdle, which we take up next.

Motionally Moving

Group activities with toddlers are hopeless. Just as you get the top toddler into position at the peak of the toddler pyramid, several on the bottom level have begun crying, pooping, or wandering away. Toddlers prefer to treat their day-care mates as objects to ignore, climb over, or hit. And just try getting a dozen of them to do anything in unison, like performing “the wave” in the audience at a roller derby! If aliens observed us humans only during toddlerhood, they might conclude that we don’t get on well in groups, and that, lacking a collaborative spirit, we will be easy prey when they invade.

But brain-thirsty aliens might come to a very different conclusion if they dropped in on a day-care center during music time. Flip on “The Wheels on the Bus Go Round and Round,” and a dozen randomly wandering, cantankerous droolers begin shaking their stinky bottoms in unison. Aliens might surmise that music is some kind of marching order, a message from the human commander to activate gyrations against an invading enemy.

Dancing toddlers, of course, play little or no role in explaining why we haven’t been invaded by aliens, but they do raise an important question. Why
do
toddlers seem to be compelled to move to the music? And, more generally, why is this a tendency we keep into adulthood? At this very moment of writing, I am, in fact, swaying slightly to Tchaikovsky’s Piano Concerto No. 1. Don’t I have better things to do? Yes, I do—like write this book. Yet I keep pausing to hear the music, and end up ever so slightly dancing. It is easy to understand why people dance when a gun is fired at their feet like in old Westerns, but music is so much less substantial than lead, and yet it can get us going as surely as a Colt 45. What is the source of music’s power to literally move us, like rats to the Pied Piper’s flute?

We can make sense of this mystery in light of the theory that music sounds like human movement. If music sounds like movement, and music makes us move, then it is not so much music that is making us move, but the sound of human movement. And
that’s
not at all mysterious!
Of course
the behaviors of others may elicit responsive actions from us. For example, if my three-year-old son barrels headlong toward my groin, I quickly move my hands downward for protection. If he throws a rubber ball at my head, I try to catch it. And if he suddenly decides he’d rather not wear his bathing shorts, I quickly pull them back up. Not only do I behave in reaction to my son’s behavior, but my behavior must be timed appropriately, lest he careen into me, bean me with a ball, or strip buck-naked and get a head start in his dash away. Music sounds like human behavior, and human behavior often elicits appropriately timed behavioral responses in others, so it is not a surprise, in light of the theory, that music elicits appropriately timed behavioral responses.