Although the definitive primary impetus for human musicality remains elusive, both Savage et al. and Mehr et al. speculate that the shadow of that impetus may be discernible within present day music thinking and behaving, albeit in two different yet complementary forms: social bonding and credible signaling. The difficulty in isolating the two theories from each other reflects the deeply entangled relationship among the multiple facets of the music learning experience. It is fruitful to consider the manner in which humans in the here-and-now become musical, actively seek opportunities for musical growth and engagement, and facilitate the musical growth of others as echoes of music's foundational place in the human experience. Taking perspectives from music learning and teaching, the evidence for music as a facilitator for social bonding is compelling among both children and adults who chose to make the ongoing study of music, either formally or informally, a part of their lives. At the same time, the emphasis placed on the clarity, precision, and, in turn, power of musical expressions that lie at the heart of many music education models (Abril & Gault, Reference Abril and Gault2008) is consistent with the demands of what Mehr et al. describe as a credible signal.

Savage et al. argue that musicality (as a “cognitive toolkit”) facilitates social bonding among larger groups more effectively and efficiently than alternative methods (e.g., grooming), yet this would arguably have first demanded a demarcation of what music was and was not. Conversely, Mehr et al.'s proposition that music evolved from its value as a credible signal presumes the presence of a signalee and immediately introduces a social component to music's beginning, one that functioned in both out-of-group (territoriality) and in-group (parent/infant dyads) interactions.

Social aspects of music making are central to the music experiences of young people (Ilari, Reference Ilari2016) and adult learners (Dabback, Reference Dabback2008), as well as music specialists (Kokotsaki & Hallam, Reference Kokotsaki and Hallam2007). As a context in which social engagement occurs, it is notable that music facilitates interpersonal dynamics that reach beyond solely bonding, both in complexity and valence. On this point, Savage et al. posit that musicality “increased the quality (depth and complexity) of existing relationships” (sect. 2.4). Musical play establishes social bonds but also facilitates within-group hierarchies and competition, much to the preference of the children taking part (Roberts, Reference Roberts2016). Groups that interact toward a common musical cause can demonstrate a high degree of social complexity. This is apparent in the intricate array of relationships observed within a music ensemble performance (D'Ausilio et al., Reference D'Ausilio, Badino, Tokay, Craighero, Canto, Aloimonos and Fadiga2012; Dineen, Reference Dineen, Gritten and King2011) and among large musical organizations (Dabback, Reference Dabback2008; Weren, Reference Weren2015). It may even extend to broad music-adjacent contexts such as that famously described by Small (Reference Small1998) in his examination of the symphony orchestra concert (although Small considered all related activities as musical). The value placed on the social cohesion facilitated by music is demonstrated by its absence. Beyond simply reducing the feeling of social closeness, a breakdown in musical synchrony can lead to stress among group members and ill feeling toward the musical leader (Lorenz, Reference Lorenz2020). This is in stark contrast to the interpersonal synchronization observed at the neural level between teacher and student in a song-learning setting (Pan, Novembre, Song, Li, & Hu, Reference Pan, Novembre, Song, Li and Hu2018).

To emphasize the compatibility of music with social bonding, Savage et al. point out that music is characterized by its reproducibility and by its accommodation for successful participation by multiple individuals. Thus, a premium is placed on musical behaviors featuring a high level of predictability (e.g., the use of regular metric patterns) and repetition (such as the employment of a small number of recurring melodic and/or rhythmic figures). Music is arguably built to be a group endeavor. This is congruent with Mehr et al. who argued that there was an evolutionary pressure placed on the clarity of a credible signal, with a coordinated signal being more discernible and stronger (with an emphasis on both synchrony and coordination, see Lee, Launay, & Stewart, Reference Lee, Launay and Stewart2020). Mehr et al. proposed that “selection should push receivers to better discriminate differences in degrees of coordination, and signalers to produce more complex coordinate signals” (sect. 4.2.1, para. 4). On a much smaller temporal scale, this is an apt description of a music curriculum. Within the active music learning context, such an emphasis on clarity of signal is evident to the point of being a fundamental truth. Achievement in music learning is demonstrated by a person's ability to perform “correctly,” in coordination with others, and in adherence to prevailing norms.

Although Mehr et al. states that “music does not directly cause social cohesion” (sect. 4.2.1, para. 14), Savage et al. predict the two demonstrate correlational (bonding increases with number of musical components) and additive (bonding greater for participatory than non-participatory experiences) properties. If musicality is inextricably linked to social bonding, a critical question might be posed whether social bonding is compromised among those for whom the learning of coordinated group music activity is difficult. Savage et al. make the case that observation of musical behaviors is sufficient to facilitate social bonding among groups too large to include only performers. Peretz (Reference Peretz2016) speculated that the reward system response to group music making may serve as an effective intervention for amusics, suggesting that context rather than musical coordination is more salient. Whether as a participant or as an observer, it may be tested whether degraded or compromised capabilities, physiological or cognitive, related to metric, rhythmic, or melodic perception result in a corresponding decrease in bonding.

Be it Cross's “floating intentionality” (Reference Cross2008) or Keil's “participatory discrepancies” (Reference Keil1987), the shared experience of music in which a multiplicity of meanings and interpretations is accommodated might be considered antagonistic to the clarity or interpretability of musical signaling. Alternatively, the proposition of music as fundamentally a means of social bonding might manifest in the present through its ability to establish and support implicit relationships that, although in cases hierarchical, do not compromise the contribution of any given individual to the collective. The earliest development of behaviors and processes supporting music may have appeared through the need to establish credible signals, but perhaps the ultimate utility of these behaviors and processes to establish and sustain social relationships lies at the heart of their distinction as music.