Tuesday, May 22, 2007

11. Standard Candles

If, as I argued in the previous post, musical style can be regarded as not only a "neutral marker" but an actively conservative force, inherently resistant to change, then it has the potential to become an especially powerful tool for the reconstruction of cultural history and, in cooperation with genetics, the various "Out of Africa" migrations of early humans.

Some geneticists have claimed that the mutation rate for certain types of DNA is statistically predictable, providing them with a kind of clock with which to estimate when certain mutations occurred. A linguistic method called Glottochronology made a similar, though more dubious, claim for language. As far as I have been able to determine, no such "internal clock" would seem to exist for musical "mutations." But there is a method from the realm of Astronomy that could, I think, be applied to music: the "standard candle."

An example of a "standard candle" would be the Cepheid Variables, a type of star with a known "signature" of variability that makes it easy to recognize. One can also calculate its absolute brightness from the frequency of the variation, a discovery that made it possible to use Cepheids as "standard candles" to determine the distance to any stars or galaxies in the same vicinity.

We can apparently do something similar to help us estimate certain dates important for cultural history. For example, the genetic estimate I've already alluded to, of 72,000 to 102,000 years ago for the initial separation of the Biaka Pygmies from the hyphothetical founder group can be used as a "standard candle" to help us determine the age of P/B style, which we could then consider to be at least 72,000 years old. We could then look for any other practices common to both Bushmen and Pygmies that might also date to the same time. Since the dates for the Bantu expansion (between 2000 and 4000 years ago) seem also to be known, that would by the same token provide us with a conservative estimate of at least 2000 years ago for the origins of mainstream Bantu style. However, the same genetic studies that gave us the Biaka dates also give us dates for the divergence of a Bantu population from Senegal ranging between 17,900 and 23,200 years ago. On that basis, we might want to revise our estimate for the origins of this musical style to some time between 2000 and 17,900 ya.

As I mentioned in my previous post, a conservative estimate for the earliest arrival of humans in the Americas is around 10,000 years ago, which could put the age of Amerindian unison/one-beat/iterative style at roughly the same date. In my essay, however, I noted a strong resemblance between the music of many native North American groups and the Australian Aborigines, who also tend to sing iteratively, in unison, with one-beat accompaniment. Many Aboriginal songs have a markedely descending or even "terraced" melodic contour, making them especially close to the Indians of the Plains and Prairie, many of whose melodies are also terraced. If both styles do indeed stem from the same cultural root, we could use the estimated genetic-archaeological date for the first entry of humans into Australia as our "standard candle." That would be somewhere between 60,000 and 40,000 years ago. Since the Australians appear to have been essentially isolated on that continent from that time until the colonial period, with little or no outside contacts, it seems safe to conclude that the common root for both traditions, assuming they have a common root, would have to be dated to some time prior to the first landing of the aboriginals on the Australian shore.

We now have a set of dates that we can use in the construction of some sort of very simple phylogenetic map for tracing the "geneology" of the above musical traditions. Using the most conservative dates, we would then place the origins of P/B style at some point prior to 72,000 years ago. The next segment would branch off the root at 40,000 years ago, as the possible origin of unison/one-beat/iterative style, with a sub-branch, signalling the origin of the Amerindian version, at some time between 40,000 and 10,000 years ago. Another, separate branch, from the original root, marking the origin of mainstream Bantu style, would begin sometime between 2000 and 17,000 years ago.

These are only a few of the possibilities for estimating the origin dates and constructing phylogenetic trees of certain musical, and associated cultural, traditions, using a "standard candle" provided by genetic and/or archaeological research.

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