Two questions about music and evolution. How did humans evolve to be musical? (last post) How does music evolve? (below)
Warning: this starts with interesting stuff about the psychology of music and evolutionary mechanisms applied to non-biological systems, but then drifts off into quite a lot about traditional music.
An experimental demonstration of how random sounds can evolve into something that seems quite musical by means of human selection. Here’s an intro to the project on Psypost: http://www.psypost.org/2012/06/on-the-origin-of-music-by-means-of-natural-selection-12336
It’s more fully written up in the paper: Evolution of music by public choice by MacCallum, Mauch, Burta, and Leroia of Imperial College London and the National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan at http://www.pnas.org/content/early/2012/06/12/1203182109.full.pdf
Published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS) in 2012. Here’s their abstract:
Music evolves as composers, performers, and consumers favor some musical variants over others. To investigate the role of consumer selection, we constructed a Darwinian music engine consisting of a population of short audio loops that sexually reproduce and mutate. This population evolved for 2,513 generations under the selective influence of 6,931 consumers who rated the loops’ aesthetic qualities. We found that the loops quickly evolved into music attributable, in part, to the evolution of aesthetically pleasing chords and rhythms. Later, however, evolution slowed. Applying the Price equation, a general description of evolutionary processes, we found that this stasis was mostly attributable to a decrease in the fidelity of transmission. Our experiment shows how cultural dynamics can be explained in terms of competing evolutionary forces.
You can find examples of the evolved music at http://darwintunes.org/ where they’ve now got up to 3,500 generations, and you can also take part in the study. The ‘selective influence’ is just asking people to rate the clips – do they like them or not? The ‘sexual reproduction’ is done by splitting and mixing the clips with each other to simulate chromosome mixing (sex is good for mixing up genes), and the ‘mutation’ is introducing a bit of random variation. So that looks like a nice model of reproductive selection, and what comes out sounds more and more like music as you go down the generations. In fact, there may even be new species evolving: a tweet today says: “Amazing stuff on the main channel right now – a whole new phenotype has emerged – inter-loop chord changes and more!” (Yes, you can follow them on twitter at darwintunes).
Well, that’s fascinating and fun but as an old folky I thought ‘Duh!: I thought everyone knew that music evolved.’ A long established theory of the development of traditional music is one of evolution with variation provided by imperfect recall and bits of musical innovation, and selection provided by people’s preference for what they would like to hear and play again, or maybe just by what sticks in memory.
Here’s the definition from the International Folk Music Council (no, I didn’t know there was one of those, either) in 1954:
..folk music is the product of a musical tradition that has been involved in the process of oral transmission. The factors that shape the tradition are i) continuity which links the present with the past; ii) variation which springs from the creative impulse of the individual or group; iii) selection by the community, which determines the form of forms in which the music survives. (Quoted in Lloyd 1975, p15)
Cecil Sharp said much the same kind of thing in 1920:
…the most typical qualities of the folk-song have been laboriously acquired during its journey down the ages, in the course of which its individual angles and irregularities have been rounded and smoothed away just as the pebble on the seashore has been rounded by the action of the waves; that the suggestions, unconsciously made by individual singers, have at every stage of the evolution of the folk-song been weighed and tested by the community, and accepted or rejected by their verdict; and the life history of the folk-song has been one of continuous growth and development, always tending to approximate the form which should be at once congenial to the taste of the community, and expressive of its feelings, aspirations, and ideals. (p. viii)
Sharp was looking it from the point of view of National Song. Lloyd, a Marxist, uses a different framework:
..the formulation is valuable for its clear suggestion of the vital dialectic of folksong creation, that is, the perpetual struggle for synthesis between the collective and individual, between tradition and innovation, between what is received from the community and what is supplied out of personal fantasy, in short, the blending of continuity and variation. (Lloyd, 1975, p16).
Gerould points out in The Ballad of Tradition (1932, 1957) that this process can also produce a range of equally admirable (in his terms: equally viable, for the evolutionary argument) variants. He does want to bring artistic judgement and ability into it:
the existence of many variants, both melodic and contextual, which are manifestly not due to haphazard, undirected substitution for what has been forgotten shows a widespread power of musical and poetic expression (p183)
…and I guess that’s fair enough. What Mississippi John Hurt or Harry Cox brought to the tradition is probably a step which goes beyond natural selection.
It also seems to me that the biological idea of hybrid vigour is shown when different musical traditions cross: what happened when Scotch-Irish ballads met African-derived music in the Appalachians*, or Toumani Daibaté (and others) combining the power of West African classical music with other traditions**.
A nice modern summary comes from the blogger The Irate Pirate in a post on his Wrath of the Grapevine blog (http://grapewrath.blogspot.co.uk/2009_03_01_archive.html, 2009)
Like most musics, I suppose, the more you listen to folk music the more you develop a taste for it. But part of the fascination that’s particular to folk music is that you’ll hear bits and pieces of one song that you could have sworn you heard in a completely different song. And you’d be right. Because folk music is an evolved music, and like humans & chimpanzees, there are uncanny similarities lurking just below the surface that point to some invisible, unknowable ancestral precedent. And, like all things subject to evolution by natural selection, the essential parts are maintained and the extraneous, inconsequential bits fall aside. What this means in terms of folk music, particularly these old traditional ballads, is that while a song may be quirky and seemingly obtuse, at some level (often a non-conscious, irrational level), the song is deeply meaningful and helps people to negotiate the trials and uncertainties of this muddled mortal existence.
And, of course, since folksong-evolution is an organic process in an oral tradition, sometimes bits and pieces get lost along the way and we’re left with only fragments (you could say this too is a product of natural selection: the part that remains is that which is most memorable). And since it is sung by people who weren’t professional musicians, it had to relate to things that everyday people could relate to, rather than abstruse musical concepts and the self-indulgent wankery that professional artists are susceptible to. The universal subjects are thus revealed: love, death, nature, heartbreak, childhood, remorse, dream/spiritual encounters, and leaving home. These themes can be found recurring in folk music and most great narrative art across time, from Homer to Shakespeare to Stan Brackage. It’s as if these subjects keep coming back because they’re the moments in our lives that stay with us, and we need songs & stories like these to help mark those moments and distill meaning from them.
So, the process that produced the Lowlands of Holland or the Leaves of Life is rather similar to the process that produced the cheetah or the kingfisher (and the warthog and the platypus, to be fair). It’s not surprising that traditional music is so good.
GeroulD, G.H. (1932, 1957) The Ballad of Tradition London: Galaxy, OUP
Lloyd, A.L. (1975) Folk Song in England St Albans: Paladin (orig. publ. Lawrence & Wishart, 1967
MacCallum, Robert M, Matthias Mauch, Austin Burt, & Armand M. Leroi (2012) Evolution of music by public choice, PNAS, no paper version yet
Available at: http://www.pnas.org/content/early/2012/06/12/1203182109.full.pdf
Sharpe, Cecil (1920) English Folk Songs, 2nd ed Novello; London
* Here’s Clarence Ashley doing CooCoo bird (music doesn’t start until 3.30):
**TD with the AfroCubism band:
..and playing Cantelowes: