What is universal about music, and what varies? We built a corpus of ethnographic text on musical behavior from a representative sample of the world’s societies, as well as a discography of audio recordings. The ethnographic corpus reveals that music (including songs with words) appears in every society observed; that music varies along three dimensions (formality, arousal, religiosity), more within societies than across them; and that music is associated with certain behavioral contexts such as infant care, healing, dance, and love. The discography—analyzed through machine summaries, amateur and expert listener ratings, and manual transcriptions—reveals that acoustic features of songs predict their primary behavioral context; that tonality is widespread, perhaps universal; that music varies in rhythmic and melodic complexity; and that elements of melodies and rhythms found worldwide follow power laws.

Probability distributions over external states (priors) are essential to the interpretation of sensory signals. Priors for cultural artifacts such as music and language remain largely uncharacterized, but likely constrain cultural transmission, because only those signals with high probability under the prior can be reliably reproduced and communicated. We developed a method to estimate priors for simple rhythms via iterated reproduction of random temporal sequences. Listeners were asked to reproduce random "seed" rhythms; their reproductions were fed back as the stimulus and over time became dominated by internal biases, such that the prior could be estimated by applying the procedure multiple times. We validated that the measured prior was consistent across the modality of reproduction and that it correctly predicted perceptual discrimination. We then measured listeners' priors over the entire space of two- and three-interval rhythms. Priors in US participants showed peaks at rhythms with simple integer ratios and were similar for musicians and non-musicians. An analogous procedure produced qualitatively different results for spoken phrases, indicating some specificity to music. Priors measured in members of a native Amazonian society were distinct from those in US participants but also featured integer ratio peaks. The results do not preclude biological constraints favoring integer ratios, but they suggest that priors on musical rhythm are substantially modulated by experience and may simply reflect the empirical distribution of rhythm that listeners encounter. The proposed method can efficiently map out a high-resolution view of biases that shape transmission and stability of simple reproducible patterns within a culture.

One sentence summary: Ethnographic text and audio recordings map out universals and variation in world music. Abstract:What is universal about music, and what varies? We built a corpus of ethnographic text on musical behavior from a representative sample of the world's societies, and a discography of audio recordings. The ethnographic corpus reveals that music appears in every society observed; that music varies along three dimensions (formality, arousal, religiosity), more within societies than across them; and that music is associated with certain behavioral contexts such as infant care, healing, dance, and love. The 2 discography, analyzed through machine summaries, amateur and expert listener ratings, and manual transcriptions, revealed that acoustic features of songs predict their primary behavioral context; that tonality is widespread, perhaps universal; that music varies in rhythmic and melodic complexity; and that melodies and rhythms found worldwide follow power laws. Main Text:At least since Henry Wadsworth Longfellow declared in 1835 that "music is the universal language of mankind" (1) the conventional wisdom among many authors, scholars, and scientists is that music is a human universal, with profound similarities across societies springing from shared features of human psychology (2). On this understanding, musicality is embedded in the biology of Homo sapiens(3), whether as one or more evolutionary adaptations for music (4, 5), the byproducts of adaptations for auditory perception, motor control, language, and affect (6-9), or some amalgam.Music certainly is widespread (10-12), ancient (13), and appealing to almost everyone (14). Yet claims that it is universal or has universal features are commonly made without citation (e.g., (15-17)), and those with the greatest expertise on the topic are skeptical. With a few exceptions (18), most music scholars, particularly ethnomusicologists, suggest there are few if any universals in music (19)(20)(21)(22)(23). They point to variability in the interpretations of a given piece of music (24-26), the importance of natural, political, and economic environments in shaping music (27)(28)(29), the diverse forms of music that can share similar behavioral functions (30), and the methodological difficulty of comparing the music of different societies (12,31,32). Given these criticisms, along with a history of some scholars using comparative work to advance erroneous claims of cultural or racial superiority (33), the common view among music scholars today (34,35) is summarized by the ethnomusicologist George List: "The only universal aspect of music seems to be that most people make it. … I could provide pages of examples of the nonuniversality of music. This is hardly worth the trouble." (36) Are there, in fact, meaningful universals in music? No one doubts that music varies across cultures, but diversity in behavior can shroud regularities emerging from common underlying psychological mechanisms. Beginning with Noam Chomsky's hypothesis that the world's languages 3 ...

Human language, as well as birdsong, relies on the ability to arrange vocal elements in novel sequences. However, little is known about the ontogenetic origin of this capacity. We tracked the development of vocal combinatorial capacity in three species of vocal learners, combining an experimental approach in zebra finches with an analysis of natural development of vocal transitions in Bengalese finches and pre-lingual human infants and found a common, stepwise pattern of acquiring vocal transitions across species. In our first study, juvenile zebra finches were trained to perform one song and then the training target was altered, prompting the birds to swap syllable order, or insert a new syllable into a string. All birds solved these permutation tasks in a series of steps, gradually approximating the target sequence by acquiring novel pair-wise syllable transitions, sometimes too slowly to fully accomplish the task. Similarly, in the more complex songs of Bengalese finches, branching points and bidirectional transitions in song-syntax were acquired in a stepwise manner, starting from a more restrictive set of vocal transitions. The babbling of pre-lingual human infants revealed a similar developmental pattern: instead of a single developmental shift from reduplicated to variegated babbling (i.e., from repetitive to diverse sequences), we observed multiple shifts, where each novel syllable type slowly acquired a diversity of pair-wise transitions, asynchronously over development. Collectively, these results point to a common generative process that is conserved across species, suggesting that the long-noted gap between perceptual versus motor combinatorial capabilities in human infants1 may arise from the challenges in constructing new pair-wise transitions.