Musical evolution in the lab exhibits rhythmic universals

Abstract

Music exhibits some cross-cultural similarities, despite its variety across the world. Evidence from a broad range of human cultures suggests the existence of musical universals 1 , here defined as strong regularities emerging across cultures above chance. In particular, humans demonstrate a general proclivity for rhythm 2 , although little is known about why music is particularly rhythmic and why the same structural regularities are present in rhythms around the world. We empirically investigate the mechanisms underlying musical universals for rhythm, showing how music can evolve culturally from randomness. Human participants were asked to imitate sets of randomly generated drumming sequences and their imitation attempts became the training set for the next participants in independent transmission chains. By perceiving and imitating drumming sequences from each other, participants turned initially random sequences into rhythmically structured patterns. Drumming patterns developed into rhythms that are more structured, easier to learn, distinctive for each experimental cultural tradition and characterized by all six statistical universals found among world music 1 ; the patterns appear to be adapted to human learning, memory and cognition. We conclude that musical rhythm partially arises from the influence of human cognitive and biological biases on the process of cultural evolution 3. Percussion instruments may have provided the first form of musical expression in human evolution. Great apes, our closest living relatives, show drumming behaviour 4 , which they can learn socially 5 , producing some human-like rhythmic sequences 6. Percussive behaviour may therefore have already been present in our ancestors some million years ago, before the split between the human and Pan lineages 2. Archaeological findings also suggest that the first human musical instrument might have been percussive, as also attested in modern hunter-gatherer societies around the world 7. This makes rhythm a particularly apt musical dimension for reconstructing crucial steps in the evolution of music. Six rhythmic features can be considered human universals, showing a greater than chance frequency overall and appearing in all geographic regions of the world. These statistical universals 1 are:

Cultural evolution of music

“…Thus, one group mimicked sexual reproduction by 363 having short audio loops recombine and mutate, then used an online survey to allow 364 listeners to mimic the process of natural selection on the resulting music, finding 365 that aesthetically pleasing music evolved from nearly random noise over the course 366 of several thousand generations solely under the influence of listener selection 367 . Using a different experimental paradigm similar to the 368 children's game Telephone, other groups found that melodies and rhythms became 369 simpler and more structured in the course of transmission, paralleling findings from 370 experimental language evolution (Ravignani, Delgado, and Kirby 2016;Jacoby and 371 McDermott 2017;Lumaca and Baggio 2017). Like biological evolution and 372 language evolution, our knowledge of musical evolution can be enhanced by 373 combining ecologically valid studies of musical evolution in the wild (i.e., in its 374 cultural context) with controlled laboratory experiments.…”

From random to regular: neural constraints on the emergence of isochronous rhythm during cultural transmission

“…This view is now supported by behavioural laboratory experiments (Ravignani et al , 2016), but neural evidence is still missing. Here, we aim to provide such evidence, using musical rhythm as a model for studying the emergence of the most widespread form of temporal regularity: isochronicity.…”

Speech rhythm as naturally occurring and culturally transmitted behavioral patterns

“…The output of “one generation of learners” is used as the model input for the “following generation,” and such iterations continue for multiple generations: (1) revealing the emergence of a structured behavior from a chaotic mix of incoherent behavioral patterns, (2) leading to the ritualization of behavior in later generations, and (3) capturing the dynamics of cultural cross‐generational transmission. Importantly, in relation to rhythmic cognition, iterated learning paradigms show the clearly biological basis of cultural transmission, which makes it difficult to determine which rhythmic aspects are naturally determined and which are culturally transmitted …”