Philosopher of science Paul Feyerabend once noted that “the more popular an idea, the less one thinks about it and the more important it becomes to examine its limitations” (Feyerabend, Reference Feyerabend1984, p. 111). This remark could be applied to idea of the evolutionary origins of music in social bonding proposed by Savage et al. in their target article. The idea has risen in popularity and acceptance over the years, partly by virtue of its intuitive appeal and partly because it ennobles music. A theory of the “evolutionary origins of music in self-isolation,” even if well-supported, might have enjoyed considerably less acclaim. In this context, Mehr et al.'s contribution offers a much-needed critical examination of prominent views on the evolution of music. By exposing a number of weaknesses in the view of the evolutionary origins of music in social bonding, it invites us to revisit some long-cherished assumptions and open up to alternative hypotheses. Not an evolutionary biologist or psychologist, I will offer a few observations and comments that are inspired by my own research on music and emotion, musical ability, and on infants' music perception rather than assessing the strengths and weaknesses of the views in question from an evolutionary standpoint.

Although mainly focusing on the view of the evolutionary origins of music in social bonding, Mehr et al. also touch on the theory of the origins of music in sexual selection. They see it as poorly supported, in part because “If music evolved to signal mate quality, then adaptations for music production should be more developed in men and adaptations for music perception should be more developed in women” (Mehr et al., target article). Although this particular prediction is difficult to test because the capacities for music production and music perception are related (e.g., Dalla Bella et al., Reference Dalla Bella, Farrugia, Benoit, Begel, Verga, Harding and Kotz2017), sex differentiation in musical behaviors and aptitudes between the sexes ought to be expected from a sexual selection point of view. Our laboratory has examined musical abilities and other music related dispositions in thousands of participants and we have found little evidence for sex differences so far (Law & Zentner, Reference Law and Zentner2012; Zentner & Strauß, Reference Zentner and Strauß2017). Using a scale that captures two components of what we term “music-mindedness,” namely liking for music and musical competence (somewhat reminiscent of the distinction music perception and production), we similarly failed to find any sex differences (Zentner, Reference Zentnerin preparation).

Mehr et al. offer a thought-provoking alternative view to the social bonding hypothesis by proposing that music evolved because it functioned as a credible signal of coalition strength, size, and coordination ability. Much of the literature on the evolution of music has focused on select animal vocalizations, notably vocal learners. A theory of the evolution music that accounts for most animal vocalizations would be both more parsimonious and more powerful than partial, species-specific accounts. One of the strengths of Mehr's proposition is that, by including territorial calls, it can integrate a broader array of animal vocalizations than the social bonding hypothesis and other prior evolutionary accounts of music. Yet one difficulty with this idea is that it hinges on the merits of the claim that “that territorial vocalizations are an evolutionary precursor to music, especially rhythmic music.” Given the importance of this claim for the authors' hypothesis on the origins of music, it receives relatively little attention. It would strengthen their position to provide a specification of the types of evidence needed to connect animal vocalizations to human music.

This is not an easy task given how little is known about the earliest forms of human music. If the way Homer's sirens sounded is anyone's guess, the picture becomes even more muddied when we go further back in the history of human music making. Somewhat ironically, both target articles provide relatively circumscribed definitions of music that may make their case more difficult to sustain than it needs to be. For instance, conventions encoded in our language, such as to say that birds sing, but not donkeys or dogs (Nettl, Reference Nettl2015), constitute biases in the understanding of music that may hamper the search for substantive connections between early human, evolved, contemporary forms of music and animal vocalizations.

A relevant but hardly discussed aspect of animal vocalizations is that they appear to be often emotionally charged. For example, tamarin calls can be broadly subdivided into those used in an affiliative context and those relating to fear and threat. In a fascinating effort to particularize such calls, Snowdon and Teie (Reference Snowdon and Teie2010) identified tritones, minor seconds, and noise as musico-acoustical markers for threat related calls. Positing a connection between animal territorial calls and music, Mehr et al. note that, in humans, vocal and instrumental music “appears in political and military contexts with analogues to territorial signaling (…); is generally not sexually differentiated (…); and, of course, is often loud.” Although music is occasionally used in bellicose contexts, the vast majority of music is not. Equally rare in human music are the harsh and dissonant features observed in many threat-related territorial calls. Relatedly, territorially relevant emotions such as fear and anger are among the most rarely experienced emotions in response to music (Juslin & Laukka, Reference Juslin and Laukka2004; Zentner, Grandjean, & Scherer, Reference Zentner, Grandjean and Scherer2008).

These findings do not necessarily undermine the authors' hypothesis of the origins of music. Still, offering a compelling explanation for why human music is structurally and emotionally so divorced from animal territorial calls would strengthen their hypothesis. Similarly, if music had a social purpose, this purpose seems to have largely vanished. Today, music is predominantly consumed in solitary contexts, and used for self-serving emotional rather than social, societal, or communicative purposes (e.g., Randall & Rickard, Reference Randall and Rickard2017). As with many evolutionary theories, it will be difficult to gather unequivocal evidence to support the origins of music in credible signaling hypothesis. Nevertheless, as scholars embrace the idea that music evolved to promote social bonding and cohesion with increasing enthusiasm, a challenge to its general sway may be just what music evolutionists need to keep their inquisitive pulse up.