Oppostion and the beginnings of melody
One of the hallmarks of swing, or rhythmic music in general, is an attribute (to paraphrase Steven Colbert) that we can call “back-and-forth-iness.” “This, then that,” “Yin, then yang,” “See, then saw…” you get the idea. Swing. Rocking back and forth. The sense of “motion” in music. This brings us to the idea of the pivot.
Where do we get our pivots?
The overtone series is a good place to start our search.
The structure of music roughly emulates the overtone series. The overtone series is derived by subdividing a string, or vibrating air column, by its series of rationic fractions. As it vibrates in whole, a string simultaneously vibrates also in half, thirds, fourths, fifths, et cetera, all the way up to infinity in theory, although in actuality the series is constrained by the limitations of the materials. It is interesting to note that these notes, when played, are referred to as “harmonics.” Another interesting thing about this is the resulting intervallic array, and the notes produced. The notes are: one octave up, an octave and a fifth, the root two octaves up, a third, the fifth again, then a note somewhere between the sixth and seventh, then the root again, then on into the scale:
I have found that this series is an excellent guide for judging the appropriateness (or the “safety”) of other note choices for a bass player – particularly for the “pivot,” which we can define as the “primary oppositional note to the root.” The first stop out on the overtone series – after the octave, which can also act as a pivot – is the fifth.
Roots and fifths. Bass players have put their kids through college playing roots and fifths. The fifth is the most common pivot (although there can be others). It’s a harmonic tone, but in the realm of the bass, it’s less harmonic than the root, and can be used to “oppose” the root in the creation of bass parts; to go back and forth to, creating a pivot.
What can we observe about these examples? What is going on rhythmically? We’re looking at the most common, default bass part known to man… yet there’s more to it than meets the eye. Which beat is the pivot on? The third beat…and, this is the most common location for a pivot, whether it’s the fifth of the chord or not. It’s halfway to the next anchor. We could describe the third beat as a rhythmic pivot, as well.