The Forest for the Tree

Stephen Jay Gould was the emeritus professor at Harvard who pioneered the concept of "punctuated equilibrium". This idea postulates that evolution is not a steady progress of growth, but is actually a pattern of lengthy stability and punctuated only momentarily by brief periods of change. These plateaus of stability are lengthy and are the predominant pattern. It may be environmental changes or changes in food or predation that facilitate species diversification. It may be, although I'm not aware that he ever said this, that genetic mutations take a fixed period until they affect key parts of the gene code that would allow for viable transformation. It may be other factors we have not even considered. But at some point a species changes.

So a few weeks ago I upgraded my computer system. In the process of this evolution, I lost the address to this blog. I also finished my 4th Jazz CD (Sandcastles, on Red Raven Records, San Diego, CA) so I listened to virtually no classical music for a month. Well, today I found the address to this blog again and here we go!

Gould doesn't look at evolution as a line that runs from a lower life form to a more complex life form. He and Darwin reporyt evolution to be a branches and bushes. Thus, early hominids branched into co-occurring species, each with its own unique adaptations. Eventually, based on environmental challenges (and maybe social challenges) one species would seem to outlast the others.

Ultimately, it is our ears that decide which branch of our harmonic tree best fits a given composition. We have sections that are stable and essentially tell us what must come next. Then we reach nodes where we can branch into any of several directions. We try out different possibilities and allow survival of the fittest to prune off the less fruitful branches.

I exemplify with the venerable circle of 5ths. It's hard to find many classical compositions that don't at some point in the piece include a step through the circle of 5ths. It simply means we go from the root and then jump a 5th higher and we keep selectin chords by stepping up a 5th higher. In the key of C, the pattern is C G Dm A Em B.... Composers also know that the circle of 5ths is the converse of the circle of 4ths. We can use the same circle and run backwards through it by jumping by 4ths: C F Dm G Em A....

Once the pattern begins we are at a point on a branch that is unchanging. It is a straight run with no diversity. The predictability of the run is comforting to the ears of the listener and that allows them to recollect their wits before darting off in a new direction. But when we reach the end of this sprout we come to a decision node. To carry the circle of 4ths too far begins to create a transition in tonality that creates excessive ambiguity. This is a new branch point. It is my job as a composer to figure out which of the new branches is most fitting for the song at the moment.

Composition is in the branches. So I'm exploring some of these branches. Part of what separates us from the preceding hominids has been our capacity to communicate not just from person to person, but across the generations. We can pass information down. We don't always do so, however. I saw a show on Concrete 2 days ago. The recipe for the finest concrete was lost when the Roman Empire collapased and was not recreated for over 1000 years. Had it been recorded successfully or put into play without interruption the world would be a far different place. This special recipe allowed concrete to harden underwater allowing for bridges, canals and far more enduring and capable structures.

To maintain progress it makes sense to record our steps, so we don't need to recreate concrete again down the road. So here are some of the choices at the branching end of a circle pattern:

Stem.............................Branches

C F Dm G Em A :
.......................................F G
.......................................F Em Dm Bdim
.......................................Dm G
.......................................Dm Em F Abdim
.......................................F G Em Am Dm G G7

Examples of these are in the accompanying mp3file: trees

Most of these branches will resolve back to the tonic of C. Each, however, takes a different path and conveys a different feel.

Note that even while the core branch is unchanging in its chord pattern, there are a thousand choices in the way each is melodized or arpeggiated. This log seems to be mainly about song structure, because that's what I am working on at the moment. Song structure is what I think about; melodies I produce based on feel. In the end, the character of each composition derives from the melodic fabric draped over the structure. No matter how graceful your sofa's frame is, it is the upholstering that is the actual contact point for the eye and the body.

So there!