If cultural drift applied to music, however, then how can we explain the extraordinary survival of a single tradition among so many groups of Pygmies and Bushmen over tens of thousands of years? And if they really thought much about it, the ethnomusicologists would have realized a long time ago that there are all sorts of traditions which have to be survivals of extremely old practices, judging from the wide distribution of certain closely related styles (or, if you prefer, musical "languages"), e.g., the Anglo-European Ballad, the Eurasian epic, the Moslem-Hindu maqam-raga complex, north Amerindian unison/iterative/one-beat, Bantu African call and response plus drum ensemble, etc. While any given melody or composition is likely to change over time or vanish entirely due to cultural drift, the musical language itself (or, if you prefer, "style") will persist. Until something happens to change it.
Explaining why musical styles persist and also why they change is (or should be) one of the great challenges of Ethnomusicology -- but not only Ethnomusicology, because this is a question that concerns (or should concern) Anthropologists, Archaeologists, Historians and anyone else with a serious interest in culture and cultural evolution.
If, thanks to all the many arguments I've already presented, we can regard P/B as a kind of "baseline" (a term Alan Lomax once used to describe the Pygmies and their music), then this tradition would probably be the best place to start. And to my mind the most fundamental questions to ask are: 1. how did this highly distinctive, complexly interactive musical tradition arise among our earliest ancestors in the first place? and 2. what happened, among the various lineages that ultimately diverged from the ancestral group, to change it?
To some extent, I've already considered both questions, speculating first on the origins of P/B beginning with post no. 21, "Music" in the Year Zero. What I noticed that seemed important was the resemblance between certain types of highly interactive primate vocalization, specifically what is called "duetting" and "chorusing," and the practice, so fundamental to P/B, of closely interlocking vocal (or instrumental) parts, or "hocket." Combine duetting and chorusing with the tendency of many primates to produce "hooting" sounds not unlike yodel, and we see, if nothing else, an opportunity for further research into some very intriguing possibilities. Unfortunately, there's not much more to be done in this area until more research has been done on primate vocalization.
As for question no. 2, I've done some speculating on that one as well, beginning with posts no. 46 and 47, which contains the following rumination:
. . . when and why did so many of the Bantu groups abandon P/B style for the type of vocal interaction now most common among them today, what is usually referred to as "call and response"? I don't think the change in musical style could have coincided with the separation from the "founding" group, because there are still certain Bantu tribes that do in fact still vocalize in P/B style -- some with yodelling as well (see map). It seems likely, therefore, that there must have been a split among the Bantu at some point after their separation from the founding group.Forgive me for quoting myself at such length, but what I wrote back in 2007 still makes a great deal of sense to me. Unfortunately it's a theory in direct contradiction with what most people consider "evolution" to mean, since that term usually implies both gradual change and, despite all the many objections of late in the name of political correctness, some sort of progress, either from the "primitive" to the "sophisticated" or, somewhat more "correctly," from the "simple" to the "complex." What I tend to see, on the other hand, at least as far as the earliest stages of musical "evolution" are concerned, are processes characterized by both sudden change -- and loss. And, what is of more general interest -- and where I'm going with all this (in case you've been wondering) -- is a consideration of similar models of sudden change and loss in the early evolution of culture itself -- or at least certain aspects of it. In other words what I'd like to explore is the way musical evolution, coupled with what we are now learning from the genetic research, might provide us with clues to the understanding of certain types of cultural process generally.
Why am I talking in terms of a "split," which implies a rather sudden occurrence, rather than a more gradual "evolutionary" process? Here, it seems to me, we come across a problem of fundamental importance to an understanding of history, both musical and otherwise. Let's assume that, after the initial separation from the "founder" group, the Bantus remained intact as a single unit over a very long time, and that during this time all sorts of gradual changes could have occurred, including musical ones, leading step by step to the replacement of P/B by call-and-response. Then, after the latter style had been established, the original Bantu population began to break up into the smaller units we are familiar with today, the groups that eventually spread throughout Africa during the "Bantu expansion."
This might seem reasonable until we ask ourselves 1. why the Pygmy and Bushmen groups did not also gradually evolve away from P/B style? 2. why Bantu vocal music ceased to evolve after the call-and-response style had been established, prior to the Bantu expansion? Everything we know about the music of traditional peoples tells us that they have a very strong tendency to maintain their traditions intact, from one generation to the next; and since the generations overlap, in some cases at intervals as short as 15 years or less, there is little opportunity for any sort of fundamental change to become established.
It seems to me, therefore, that there must have been a split at some point, something rather sudden, that divided the Bantu into two groups, those that maintained the original P/B style and those that for some reason were not able to maintain it. This is in line with an approach to evolution generally that's come into prominence in recent years, known as "punctuated equilibrium," very close in theory to the notion being promoted nowadays among the geneticists, the "population bottleneck." What's implied is that some small part of an originating population becomes isolated from the main group, possibly as a result of a dispute, or warfare, or some natural catastrophe, etc. . . .
Thus, the call-and-response polyphony now so common among so many Bantu groups, could have had its origin in some relatively sudden event now lost to history, that produced a new type of population with a somewhat different cultural outlook from its predecessor. The new outlook could also have led to new types of complexity along different lines, such as the proliferation of the many different instrumental traditions now found among so many Bantu groups, but not Pygmies and Bushmen.
(to be continued . . . )