Both target articles in this dual treatment focus on the importance of music performance for engaging in collective behaviors. Although the target papers did not place great emphasis on individual differences in performance ability, these differences are clearly relevant. In particular, the music and social bonding (MSB) hypothesis proposed by Savage and colleagues proposes that collective musical performance promotes social bonding, which in turn may have yielded survival benefits to our species. If music performance promotes social bonding, and social bonding promotes evolutionary fitness, then we may make predictions about music performance ability. By this logic, we may predict that the ability to perform music (in general) emerges spontaneously in development, that this ability is widespread in the population, and that the lack of this ability may be associated with reproductive costs.

Singing is arguably the best form of music performance on which to test these predictions. In contrast to other forms of music performance, singing does not require learning of a human-made instrument and thus may emerge without any specialized training. Furthermore, singing involves the ability to regulate actions along both dimensions cited as important for social bonding in the MSB hypothesis: synchronization and harmonization. I focus here on the latter dimension.

Singing in harmony requires accurate tuning of vocal pitch control, or pitch accuracy. If singing in accurately arose from a process of gene-culture coevolution, one would expect singing accuracy to be widespread and learned early in life without considerable intervention. Singing does emerge spontaneously in children at around the same time as language acquisition appears (Stadler Elmer, Reference Stadler Elmer, Russo, Ilari and Cohen2020). By adulthood, most individuals appear able to match pitch within the boundaries set by their culture's tuning system. Tests of singers matching pitch within equal tempered tuning (which dominates Western music) suggests a majority can match pitch within a musical semitone. For instance, a recent large-scale study of over 1,000 individuals found that roughly 1/3 of participants matched over 90% of pitches within these boundaries on average (Pfordresher & Demorest, Reference Pfordresher and Demorest2021). By contrast, relatively few participants exhibit a dominant tendency to deviate from a target pitch by a half semitone or more (the dividing line between pitch classes in the equal tempered scale). In the aforementioned sample, only 25% of participants exhibited this tendency; a figure that accords well with other reports (Dalla Bella, Giguère, & Peretz, Reference Dalla Bella, Giguère and Peretz2007; Hutchins & Peretz, Reference Hutchins and Peretz2012; Pfordresher & Brown, Reference Pfordresher and Brown2007; Pfordresher, Brown, Meier, Belyk, & Liotti, Reference Pfordresher, Brown, Meier, Belyk and Liotti2010). Existing data, therefore, suggest most humans should be able to harmonize within acceptable limits as per the claims of MSB hypothesis.

Given the fact that accurate singing is widely represented in the population, thus facilitating harmonization, one might predict that collective singing is widespread. Unfortunately, self-evaluation of singing in Western cultures tends to run against the levels of accuracy found in the data, and this may suppress participation in collective singing. Pfordresher and Brown (Reference Pfordresher and Brown2007) found that in a sample of over 1,000 psychology undergraduates in Texas, 59% believed they were unable to imitate a melody via singing. In the more recent large data set discussed above (Pfordresher & Demorest, Reference Pfordresher and Demorest2021), only 34% agreed with the claim “I am a good singer” whereas 62% agreed with the claim “I enjoy singing.” Although self-assessments did correlate with singing accuracy in this data set, there is clearly a disconnect between overall levels of self-evaluation and levels of pitch accuracy. These dissociations can have significant consequences given that self-assessment of musical skill predicts future musical participation during late childhood (Demorest, Kelley, & Pfordresher, Reference Demorest, Kelley and Pfordresher2016). Reported experiences of inaccurate singers of their early choral singing experiences tell of significant embarrassment and avoidance of future singing (Welch, Reference Welch and McPherson2006). Thus, if collective singing is beneficial to social bonding and to our species, this strong tendency in Western culture may have considerable negative consequences.

This leads to a prediction of the MSB hypothesis that is less clearly supported: What are the consequences of music production deficits, including inaccurate singing? The fact that a trait may have had adaptive value in the past does not necessarily mean that the success of modern humans relies on this trait; nevertheless, the importance of traits in modern life is often held up as evidence for such claims (as is the case for language, for instance). Pinker's (Reference Pinker1997) speculations about the non-adaptive nature of music, for instance, arose in part from the lack of evidence that music plays a fundamental role in modern-day survival. In the case of singing, the evidence is mixed. To date, there has been no evidence that inaccurate singers, or individuals with other deficits such as congenital amusia, fare worse in life than others. On the other hand, participation in singing may promote well-being at a physiological level, via reduction of cortisol secretion (Grebosz-Haring & Thun-Hohenstein, Reference Grebosz-Haring and Thun-Hohenstein2018; Kreutz, Bongard, Rohrmann, Hodapp, & Grebe, Reference Kreutz, Bongard, Rohrmann, Hodapp and Grebe2004), the release of oxytocin (Keeler et al., Reference Keeler, Roth, Neuser, Spitsbergen, Waters and Vianney2015), and through the promotion of social relationships.

Evidence from research on singing accuracy among modern Westerners thus accords with the MSB hypothesis in some ways but not others. More important, the MSB hypothesis helps to place research on singing accuracy in an informative broader context. Ultimately, although pitch accuracy is an important component of musical communication, it may be the case that the evolution of music was not so much based on the ability to perform accurately but may instead be rooted in the benefits of engaging in this collective activity. The fact that feedback from multiple singers may lead to a collective chorusing effect that obscures accuracy of an individual singer supports a limited role for accuracy of an individual. Moreover, fine-grained tuning of singing is negligibly related to the esthetic quality of singing (Hutchins, Roquet, & Peretz, Reference Hutchins, Roquet and Peretz2012; Pfordresher & Brown, Reference Pfordresher and Brown2017). If music evolved to be participatory, those of us in Western nations may wish to reconsider the current value placed on virtuoso solo performances.