Key Issues: The Big 5

How can we measure stylistic similarity between different musics, and how can this information be used to classify musical styles into groupings so as to create a musical map of the world? This raises two broad issues: classification procedures and clustering procedures.

Classification procedures attempt to characterize the degree of similarity among elements of a set. Because musical systems are complex combinations of features (e.g., pitch, rhythm, instruments, performance style), the classification of music is strongly tied in with a cognitive understanding of the basic sub-systems that comprise music. As a result, classification schemes vary depending upon which musical features are included for consideration, and how the included features are measured and quantified. Different features require different metrics. For example, a classification of interval sizes would occur along a continuous dimension whereas a classification of rhythm-types would most likely be done with regard to a series of categorical sub-types.

Stylistic clusters and musical maps. While classification procedures are able to quantify the musical similarity between any two songs, the more important objective of classification is to create stylistic clusters of entire repertoires. These clusters can be thought of as “music families”, analogous to language families in linguistics. In the most general application of this approach, these stylistic groupings can be mapped onto geographic and/or ethnographic groupings so as to generate a musical map of the world as well as to elucidate the historical study of human population movements and interactions, as mentioned in Issue 4 below. In addition, cultures differ in their degree of musical diversity, with some cultures having relatively homogeneous repertoires and others having very diverse ones. This analysis can help characterize the diversity of musical repertoires within and between cultures.

What are the mechanisms of musical change and stasis? How do musical forms emerge or become extinct over time? How does one musical style give rise to another? By what processes have musics diversified over time and location to create the geographic distribution of musical styles that currently exists? The study of music’s cultural evolution attempts to understand the relationships between musics at both the “phenetic” (surface similarity) and “phylogenetic” (evolutionary) levels. Sometimes similar musical features will emerge independently in musics that are historically unrelated, whereas in other cases closely related musics will have very different musical features.

As with the discussion of classification in Issue 1, an analysis of music’s cultural evolution requires first and foremost a cognitive commitment to a theory of the sub-systems that make up music. With such an understanding in mind, the issue becomes how musical systems undergo change over time and location. This can be applied diachronically to individual cultures (e.g., changes in musical style over generations), but the more challenging task is to characterize the processes of musical change that occur as cultures come into contact, either directly or through mass-media exposure. A frequent result of this contact is the creation of musical fusions (syncretisms, hybrids, admixtures). A fundamental issue for this analysis relates to the symmetry of musical change: do all musical features change in parallel (i.e., coevolution of features) or can certain musical features change independently of others? If it is the latter, what are the rules by which such fusions can occur?

The study of music’s cultural evolution also considers such issues as the emergence and extinction of musical forms, and the degree of musical diversity within and between cultures. For example, cultures differ with regard to the musical genres that their repertoires contain. Cultures can change musically by acquiring or losing genres, for example through cultural contact (e.g., conquest can lead to suppression of native forms and imposition of the conqueror’s forms). In addition, genres differ with regard to their stability and their tempo of change. Religious forms tend to evolve slowly whereas popular forms tend to evolve quickly.

Which musical features are found most universally across cultures, and which are more variable and culture-specific? Any approach to musical universals is critically dependent upon how we choose to describe music, as explained in Issue 1 above. Therefore, the study of universals requires a commitment to some notion of classification. This touches upon a cognitive understanding of the sub-systems of music. In addition, it touches upon notions of “invariant features” in music that may have their roots in specificity for these sub-systems in the human brain and ultimately human genome.

An understanding of musical universals is one of the key objectives of comparative musicology, one that can contribute to our anthropological understanding of music. While many different types of evidence can be presented to bolster arguments about universals, the study of musical universals must be based, first and foremost, on a comparative analysis of musics cross-culturally. It cannot be based exclusively on cognitive psychology, child development, neuroimaging findings, evolutionary arguments, or comparisons between human and animal behavior. All of those findings can provide critical support to arguments about musical universals, but the basic evidence must come from synthesizing information from the musics of as many cultures as possible. In other words, musical universals are the proper domain of comparative musicology and are one of its most important products.

A number of biological and cultural features have been successfully used as markers of human population movements having occurred over the course of tens of thousands of years. These features include not only genes (such as mitochondrial and Y chromosome DNA) but cultural features such as languages and physical artefacts. Music has an amazing, but untapped, potential to serve as a marker of human migrations. Music is a universal feature of human cultures but shows a large amount of diversity both between and within cultures. Geographic patterns of musical diversity can be used to enlighten the history of population movements and interactions.

This area interfaces with the cultural evolution of music (Issue 2 above) by considering the global spread of human musical styles from the time of origin. Is there a single root to the human musical tree or instead multiple roots? Curt Sachs talked about three primordial musical styles (pathogenic, melogenic and logogenic), Alan Lomax made an evolutionary distinction between two contrastive musical styles (African and Siberian) that he believed served as the two major sources of global musical diversity, and Victor Grauer proposed that human songs, like human genes, spread from a single origin in sub-Saharan Africa.

Not surprisingly, migrational analysis is the most synthetic of the issues discussed on this page, as it requires 1) a detailed cross-cultural analysis of musics, 2) classification of musics into groupings, 3) geographic mapping of musical styles, 4) cultural-evolutionary models of musical diversification and admixture in cases of cultural contact, and – at its best – 5) cross-domain comparisons between musical diversity and diversity in areas such as linguistics and genetics. It is comparative musicology at its most integrative and applied.

What is music, and how did it evolve? Biological approaches to the origins of music come in two basic varieties: structural/phylogenetic approaches and functional/Darwinian approaches.

Structural or phylogenetic approaches consider the evolutionary history of the human species, and how music emerged in anatomically modern humans perhaps millions of years ago. Many phylogenetic models deal with the evolutionary relationship between music and language: are their evolutions intertwined or did they evolve independently? Phylogenetic approaches often look to primate models of human behavioural evolution for ideas about precursor capacities that may have underlain musical evolution, including social features related to group structure and interaction. They also look to animal vocalizations – most especially forms of singing – for ideas about homology and analogy in music evolution. In addition, they give consideration to genetic approaches to human musicality.

Functional or Darwinian approaches consider the functional consequences of music for the individuals and groups that make it, and how music may have supported the survival of our ancestors. In other words, they look for the adaptive properties of music in terms of music’s benefits and costs. These approaches typically consider the three major Darwinian mechanisms of natural selection, sexual selection, and group selection. Some theorists reject the biological adaptiveness of music and argue instead that music is an offshoot of language evolution or that it is a cultural creation lacking biological specificity.