Only One Finger Needed

Piano recitals for six‑year‑olds tend to be one‑finger events, each child wielding his or her favorite finger to poke out the melody of some nursery rhyme. If one didn’t know much about human music and had only been to a kiddie recital, one might suspect that this is because kids are given especially simple melodies that they can eke out with only one finger. But it is not just kindergarten‑recital melodies that can be played one note at a time, but nearly all melodies. It appears to be part of the very nature of melody that it is a strictly sequential stream of pitches. That’s why, even though most instruments (including voice, for the most part) are capable of only one note at a time, they are perfectly able to play nearly any melody. And that’s also why virtually every classical theme in Barlow and Morgenstern’s Dictionary of Musical Themes has just one pitch at a time.

Counterexamples to this strong sequential tendency of melody are those pieces of music having two overlapping melodies, or one melody overlapping itself, as in a round or fugue. But such cases serve as counterexamples that prove the rule: they are not cases of a single melody relying on multiple simultaneous notes, but, rather, cases of two simultaneously played single melodies, like the sounds of two people moving in your vicinity.

Could it be that melodies are one note at a time simply because it is physically difficult to implement multiple pitches simultaneously? Not at all! Music revels in having multiple notes at a time. You’d be hard put to find music that does not liberally pour pitches on top of one another–but not for the melody.

Why is melody like this? If chords can be richly complex, having many simultaneous pitches, why can melodic contour have only one pitch at a time? There is a straightforward answer if melodic contour is about the Doppler pitch modulations due to a mover’s direction relative to the listener. A mover can only possibly be moving in a single direction at any given time, and therefore can have only a single Doppler shift relative to baseline. Melodic contour, I submit, is one pitch at a time because movers can only go in one direction at a time. In contrast, the short‑time‑scale pitch modulations of the chords are, I suggested earlier in the chapter, due to the pitch constituents found in the gangly bangs of human gait, which can occur at the same time. Melodic contour, I am suggesting, is the Doppler shifting of this envelope of gangly pitches.