Harnessed: How Language and Music Mimicked Nature and Transformed Ape to Man (17 page)

Figure 20
. The first note is on the beat, but because it is an eighth note (lasting only half a beat), all the subsequent quarter notes (which are a beat in length) are struck on the off beat. You feel the beat occurring between each subsequent note, despite there being no note on the beat.

The beat is the solid backbone of music, so strong it makes itself felt even when not heard. And the beat is special in other ways. To illustrate this, let’s suppose you hear something strange approaching in the park. What you find unusual about the sound of the thing approaching is that each step is quickly followed by some other sound, with a long gap before the next step.
Step-bang
 . . . . . .
Step-bang
 . . . . . . “What on Earth
is
that?” you wonder. Maybe someone limping? Someone walking with a stick? Is it human at all?! The strange mover is about to emerge on the path from behind the bushes, and you look up to see. To your surprise, it is simply a lady out for a stroll. How could you not have recognized that?

You then notice that she has a lilting gait in which her forward-swinging foot strikes the ground before rising briefly once again for its proper footstep landing. She makes a hit sound immediately
before
her footstep, not immediately after as you had incorrectly interpreted.
Step
 . . . . . .
bang-Step
 . . . . . .
bang-Step
 . . . . . . Her gait does indeed, then, have a pair of hit sounds occurring close together in time, but your brain had mistakenly judged the first of the pair of sounds to be the footstep, when in reality the
second
in the pair was the footstep. The first was a mere shuffle-like floor-strike during a leg stride. Once your brain got its interpretation off-kilter, the perceptual result was utterly different: lilting lady became mysterious monster.

The moral of this lilting-lady story is that to make sense of the gait sounds from a human mover, it is
not
enough to know the temporal pattern of gait-related hit sounds. The lilting lady and mysterious monster have the
same
temporal pattern, and yet they sound very different. What differs is
which
hits within the pattern are deemed to be the
footstep
sounds. Footsteps are the backbone of the gait pattern; they are the pillars holding up and giving structure to the other banging gangly sounds. If you keep the temporal pattern of body hits but shift the backbone, it means something very different about the mover’s gait (and possibly about the mover’s identity). And this meaning is reflected in our perception.

If musical rhythm is like gait, then the feel of a song’s rhythm should depend not merely on the temporal pattern of notes, but also on where the beat is within the pattern. This is, in fact, a well-known feature of music. For example, consider the pattern of notes in Figure 21.

Figure 21
. An endlessly repeating rhythm of long, short, long, short, etc., but with neither “long” nor “short” indicated as being on the beat. One
might
have thought that such a pattern should have a unique perceptual feel. But as we will see in the following figure, the pattern’s feel depends on where the beat-backbone is placed onto it. Human gait is also like this.

One might think that such a never-ending sequence of long-short note pairs should have a single perceptual feel to it. But that same pattern sounds very different in the two cases shown in Figure 22, which differ only in whether the short or the long note marks the beat. The first of these sounds jarring and inelegant compared to the second. The first of these is, in fact, like the mysterious monster we imagined approaching a moment ago, and the second is like the lilting lady the mover turned out to be.

Figure 22
.
(a)
A short-long rhythm, which sounds very different from (and less natural than) the long-short rhythm in
(b)
.

Music, like human gait-related sounds, cannot have its beat shifted willy-nilly. The identity of a gait depends on
which
hits are the footsteps, and, accordingly, the identity of a song depends on which notes are on the beat. And when a beat is not heard, the brain infers its presence, something the brain also does when a mover’s footstep is inaudible.

There are, then, a variety of suspicious similarities between human gait and the properties of musical rhythm. In the upcoming section, we begin to move beyond rhythm toward melody and pitch. We’ll get there by way of discussing how chords may fit within this movement framework, and how choreography depends on more than just the rhythm.

Although we’re moving on from rhythm now, there are further lines of evidence that I have included in the Encore, which I will only provide teasers for here:

Encore 1: “The Long and Short of Hit”
Earlier in this section I mentioned that the short-long rhythm of the mysterious monster sounds less natural than the long-short rhythm of the lilting lady. In this part of the Encore, I will explain why this might be the case.

Encore 2: “Measure of What?”
I will discuss why changing the measure, or time signature, in music modulates our perception of music.

Encore 3: “Fancy Footwork”
When people change direction while on the move, their gait often can become more complex. I show that the same thing occurs in music: when pitch changes (indicative, as we will see, of a
turning
mover), rhythmic complexity rises.

Encore 4: “Distant Beat”
The nearer movers are, the more of their gait sounds are audible. I will discuss how this is also found in music: louder portions of music tend to have more notes per beat.

Gangly Chords

Earlier in this chapter, we discussed how footsteps and gangly bangs ring, and how these rings tend to have pitches. I hinted then that it is the Doppler shifting of these pitches that is the source of melody, something we will get to soon in this chapter. But we have yet to talk about the other principal role of pitch in music—harmony and chords.

When pitches combine in close temporal proximity, the result is a distinct kind of musical sound called the chord. For example, C, E, and G pitches combine to make the C major chord. Where do chords fit within the music-is-movement theory? To begin to see what aspect of human movement chords might echo, consider what happens when a pianist wants to get a rhythm going. He or she could just start tapping the rhythm on the wood of the piano top, but what the pianist actually does is play the rhythm via the piano keys. The rhythm is implemented with pitches. And furthermore, the pianist doesn’t just bang out the rhythm with any old pitches. Instead, the pianist picks a
chord
in which to establish the rhythm and beat. What the pianist is doing is analogous to what a guitarist does with a strum. Strums, whether on a guitar or a piano, are both rhythm
and
chord.

My suspicion is that rhythm and chords are two distinct kinds of information that come from the gangly banging sounds of human movers. I have suggested in this chapter that rhythm comes from the temporal pattern of human banging ganglies. And now I am suggesting that chords come from the combinations (or perhaps the constituents) of pitches that occur among the banging gangly rings. Gait sounds have temporal patterns
and
pitch patterns, and these underlie rhythm and chords, respectively. And these two auditory facets of gait are informative in different ways, but both broadly within the realm of “attitude” or “mood” or “intention,” as opposed to being informative about the direction or distance of the mover—topics that will come up later in regard to melody and loudness, respectively.

If rhythm and chords are each aspects of the sounds of our ganglies, then we should expect chords to cycle through their pitches on a time scale similar to that of the rhythm, and time-locked to the rhythm; the rhythm and chord should have the same time signature. For example, in an Alberti chord/rhythm pattern, one’s left hand on the piano might play the notes [
C
G
E
G][
C
G
E
G][
C
G
E
G], where each set of square brackets shows a two-beat interval, and bold type and underlines indicate the emphases in the rhythm. One can see that the same two-beat pitch pattern and rhythm repeats over and over again. The pitch sequence and the rhythm have the same
2
/
4
time signature. It is much rarer to find chords expressed in a way that mismatches the rhythm, such as the following case, where the chord is expressed as a repeated pattern of three pitches—C-G-E—and thus the two-beat rhythm cycles look like [
C
G
E
C][
G
E
C
G][
E
C
G
E]. In this case, notice that the first two-beat interval—the rhythm’s cycle—has the pitch sequence CGEC, but that the second one has, instead, GECG. The pitch cycle for the chord is not matched to the rhythm’s cycle. In real music, if the rhythm is in
2
/
4
time, then the chord will typically not express itself in ¾ time. Rhythm and chords tend to be locked together in a way that suggests they are coming from the same worldly source, and therefore the arguments in this chapter lead one to speculate that both rhythm
and
chords come from, or are about, our gangly banging sounds.

We can also ask which pitch within the expressed chord is most likely to be the one played on the beat. For human movers, the lowest-pitched gangly bang we make is usually our footsteps. For music and the rhythmic expression of chords, then, we expect that the pitch played on the beat will tend to be lower than that played between the beats. Indeed, chords are usually caressed starting on the lowest expressed pitch (and often on the chord’s tonic, which in a C major chord would be the C pitch). Chords are, again, like gangly rings, with the lowest pitch ringing on the beat.

Consider yet another attribute of human gait: our gangly bangings can occur
simultaneously
. Multiple parts of a mover’s body can be clattering at the
same
time, and even a single bang will cause a ring on both the banger and the banged. So we should expect that the auditory mechanisms evolved for sensing gait would be able to process gait from the input of multiple simultaneous pitches. Consistent with this, the pitches within a chord are commonly played simultaneously, and our brains can make perfect sense of the simultaneously occurring notes. Pitch modulations that are part of the melody, on the other hand, almost never occur simultaneously (as we will discuss later).

The idea that musical chords have their foundation in the pitch combinations heard in the banging gangly sounds of human movers is worth investigating further. However, there are a wide variety of phenomena concerning chords that one would hope to explain, and that I currently have no theoretical insights into how to explain based on the raw materials of our ganglies. The laboratory of Dale Purves at Duke University has carried out exciting research suggesting that the human voice may explain the signature properties of the diatonic scale, and one might imagine persuasive explanations for chords emerging from his work. In fact, people do often vocalize while they move and carry out behaviors, and one possibility is that chords are not about gangly bangs at all, but about the quality of our vocalizations. The advantage of looking to gangly bangs as the foundation for chords, however, is that banging ganglies are time-locked to footsteps, and thus intrinsically note-like. Human vocalizations, however, are not time-locked to our footsteps, and also lack a clear connection to the between-steps movements of our banging ganglies. If chords were driven by vocalizations, we would not be able to explain why chords are so wedded to the rhythm, as demonstrated above. If one can find chords in our ganglies, then it allows for a unified account: our banging ganglies would explain
both
rhythm and chords—and the tight fit between them.

Chords, I have suggested, may have their origins in the pitches of the complex rings given off by gangly human movers. Later in the chapter, I will suggest that the pitch modulations in melody, in contrast, come from the Doppler shifting of the envelope of those gangly pitches.

Choreographed for You

Choreography is all about finding the right match between human movement and music. I had always figured it wasn’t the music as a whole that must match people’s movement so much as it was just the
rhythm and beat
. Get the music’s bangs in line with the people’s bangs—that’s all choreographers needed to care about. But I now realize there’s a great deal more to it. A lot of what matters in good choreography is not the rhythm and beat at all. The melodic contour matters, too, and so does the loudness. (To all you choreographers who already know this, please bear with me!)

Why should musical qualities beyond rhythm and beat matter to choreography? Because there are sound qualities beyond our intrinsic banging gangly sounds that also matter for sensing human movers. For example, suppose you and I are waiting for an approaching train, but you are 100 yards farther up the tracks (toward the approaching train) than I am. You and I will hear the same train “gait” sounds—the chugs, the rhythmic clattering of steel, and so on—but
you
will hear the train’s pitch fall (due to the Doppler effect) before I hear it fall. Now imagine that I am wearing headphones connected to a microphone on your lapel, so that at my position along the tracks I am listening to the sounds
you
are hearing at your position along the tracks. The intrinsic gait sounds of the train would be choreographed appropriately with my visual perception of the train, because those gait sounds don’t depend on the location of the listener. But my headphone experience of the
pitch and loudness
contours would no longer fit my visual experience. The train’s pitch now begins falling too early, and will already approach its lowest going-away-from-me pitch before the train even reaches me. The train’s loudness is also now incorrect, reaching its peak when the train is still 100 yards from reaching me. This would be a deeply ecologically incoherent audiovisual experience; the auditory stream from the headphones would not be choreographed with the train’s visible movements, even though the temporal properties—the beat and rhythm—of the train’s trangly bangings are just as they should be.