Social bonding is the primary focus of Savage et al.'s approach to “why music?” During their discussion of ancestral bonding mechanisms, they mention play (sects. 2.1 and 6.2) but only in passing. Play is, like music, a human universal, and is also found in other species. The literature on the nature of play across the animal kingdom (cf. Burghardt, Reference Burghardt2005; Graham & Burghardt, Reference Graham and Burghardt2010) parallels many of the questions and issues surrounding music's evolutionary purpose as discussed in these target articles. To connect play with music and social bonding, let us begin with the place of groove in Savage et al.'s framework.
In Figure 2 of Savage et al., note how musical features and mechanisms connect with one another through their inputs and outputs. At the level of “Musical Features,” the box marked “Groove” is almost unique in that its influences on the system – through its connections to “Dance” – are bidirectional and at its own level; only the units at the level of “Proximate Neurobiological Underpinnings” parallel this. Musical features suggested to subserve groove include entrainment to a recurring pattern of beats and larger rhythmic units, hierarchically organized (sect. 4.1, para. 2). These give rise to expectations which guide and govern responses to the music. Groove, then, is described as an emergent property of interactions of the predictable and the unpredictable in music; groove feeds into dance, which in turn serves group bonding and coherence. Dance is action, and Savage et al. focus on synchrony and shared, coordinated actions. But, let us consider how variable and asynchronous action also play a part in the construction of groove and provide a connection with social play.
The focus on synchronous group action in these articles deemphasizes the ways in which the variability of human performance – variability stemming from intention, habit, or random factors such as motor noise – allows the contribution of individuals to be audible even in relatively large group settings. Music, an auditory display of human action, leverages the rapidity of processing in the auditory system to enable the perception of the presence, action, and interaction of multiple performers, concurrent rather than turn-by-turn as in speech. Swift and omnidirectional, audition registers smaller and larger variations in sound coming from throughout the acoustic environment. Such variations may be at the compositional level (the main perspective in these target articles) or at the level of performance.
From the perspective of auditory scene analysis (Mehr et al., sect. 3.1 via Trainor, Reference Trainor and Honing2018; see also Bregman, Reference Bregman1994), listeners partition musical soundscapes – continuous, quickly-changing amplitudes – into features or events such as notes, lines, and motives. Spectral similarity/dissimilarity, frequency proximity/distance, and temporal proximity/distance are crucial low-level features the auditory system processes, along with learned and culturally-situated musical schemas. From a schematic-processing standpoint, predictability and variability of rhythmic patterning are primary sources of groove (e.g., Witek, Clarke, Wallentin, Kringelbach, & Vuust, Reference Witek, Clarke, Wallentin, Kringelbach and Vuust2014), exemplary of “levels of rhythmic complexity and expectation violation” (sect. 4.1, para. 2). Attention can, however, be captured and guided and expectation manipulated by other kinds of musical patterning. These include sequences of timbres, whether produced by one performer's drum kit or by an ensemble of different instrumental or vocal timbres (Ashley, Reference Ashley, Fabian, Timmers and Schubert2014) as well as timespans that begin with relatively predictable elements before becoming more variable and then more predictable once more (Ashley, Reference Ashley, Fabian, Timmers and Schubert2014; Danielsen, Reference Danielsen2006).
The flux of fixedness and variability serve to differentiate individual performers' actions from one another and the sounding whole. Individuals' contributions may be detected from: chorusing, or not-quite unison in some musical line; distinctive timbres or musical figures identifying individual, discrete “sound sources”; and asynchrony in attack or spectral evolution, where joint action does not completely efface minute, audible differences between performers' actions. The ways in which performers are asynchronous with one another has been theorized as “participatory discrepancies” (Keil, Reference Keil1987) and proposed as fundamental to emergent groove. Such divergences from synchrony are additional instances of “levels of rhythmic complexity and expectation violation,” albeit at a “microtiming” temporal level which is faster than that of musical notation. Performance, in addition to composition, creatively and continuously modulates music as auditory display, with the actions and interactions of performers both predictable and unexpected – essential to groove and musical engagement beyond groove. There's a reason why we speak of “playing” music: it captures the nature of creative action between individuals well.
And so, I turn again to some suggestions of parallels between music and play. The social/group outcomes in Savage et al.'s framework parallel those proposed by researchers studying social play in nonhuman species. Theories of the origins and functions of animal play are varied (Bekoff & Byers, Reference Bekoff and Byers1998; Burghardt, Reference Burghardt2005) and our consideration here is, perforce, limited. We note that nonhuman species' actions in social play have been proposed as social bonding mechanisms (Bekoff, Reference Bekoff1984). One prominent theory of Spinka, Newberry, and Bekoff (Reference Spinka, Newberry and Bekoff2001) draws intriguingly close to Savage et al.'s framework, proposing that social play in animals trains organisms for responding to the unexpected. In playful interaction, animals find themselves not in complete control and so Spinka and colleagues propose that play “enhances the ability of animals to cope emotionally with unexpected situations,” is “emotionally exciting … and rewarding, maybe even pleasurable, while at the same time being relaxed … producing the complex emotional state that is referred to as ‘having fun’ in human folk psychology.” Finally, they consider play a “cognitively demanding activity” which “requires frequent and rapid assessment and reassessment of qualitatively different situations” (pp. 144–145). These descriptions fit human musicking as well as they do animal play.
Although one may seek insights into evolutionary processes by comparative studies, it seems well to conclude by connecting human play to musicking. A recent review proposes that “What might be distinctive about human play is that people not only exploit their existing knowledge about how to explore … but also explore new ways to explore” (Chu & Schulz, Reference Chu and Schulz2020, p. 332). The myriad ways humans have made, and continue to make, so many kinds of music from a handful of common starting points richly testifies to such explorations.
Social bonding is the primary focus of Savage et al.'s approach to “why music?” During their discussion of ancestral bonding mechanisms, they mention play (sects. 2.1 and 6.2) but only in passing. Play is, like music, a human universal, and is also found in other species. The literature on the nature of play across the animal kingdom (cf. Burghardt, Reference Burghardt2005; Graham & Burghardt, Reference Graham and Burghardt2010) parallels many of the questions and issues surrounding music's evolutionary purpose as discussed in these target articles. To connect play with music and social bonding, let us begin with the place of groove in Savage et al.'s framework.
In Figure 2 of Savage et al., note how musical features and mechanisms connect with one another through their inputs and outputs. At the level of “Musical Features,” the box marked “Groove” is almost unique in that its influences on the system – through its connections to “Dance” – are bidirectional and at its own level; only the units at the level of “Proximate Neurobiological Underpinnings” parallel this. Musical features suggested to subserve groove include entrainment to a recurring pattern of beats and larger rhythmic units, hierarchically organized (sect. 4.1, para. 2). These give rise to expectations which guide and govern responses to the music. Groove, then, is described as an emergent property of interactions of the predictable and the unpredictable in music; groove feeds into dance, which in turn serves group bonding and coherence. Dance is action, and Savage et al. focus on synchrony and shared, coordinated actions. But, let us consider how variable and asynchronous action also play a part in the construction of groove and provide a connection with social play.
The focus on synchronous group action in these articles deemphasizes the ways in which the variability of human performance – variability stemming from intention, habit, or random factors such as motor noise – allows the contribution of individuals to be audible even in relatively large group settings. Music, an auditory display of human action, leverages the rapidity of processing in the auditory system to enable the perception of the presence, action, and interaction of multiple performers, concurrent rather than turn-by-turn as in speech. Swift and omnidirectional, audition registers smaller and larger variations in sound coming from throughout the acoustic environment. Such variations may be at the compositional level (the main perspective in these target articles) or at the level of performance.
From the perspective of auditory scene analysis (Mehr et al., sect. 3.1 via Trainor, Reference Trainor and Honing2018; see also Bregman, Reference Bregman1994), listeners partition musical soundscapes – continuous, quickly-changing amplitudes – into features or events such as notes, lines, and motives. Spectral similarity/dissimilarity, frequency proximity/distance, and temporal proximity/distance are crucial low-level features the auditory system processes, along with learned and culturally-situated musical schemas. From a schematic-processing standpoint, predictability and variability of rhythmic patterning are primary sources of groove (e.g., Witek, Clarke, Wallentin, Kringelbach, & Vuust, Reference Witek, Clarke, Wallentin, Kringelbach and Vuust2014), exemplary of “levels of rhythmic complexity and expectation violation” (sect. 4.1, para. 2). Attention can, however, be captured and guided and expectation manipulated by other kinds of musical patterning. These include sequences of timbres, whether produced by one performer's drum kit or by an ensemble of different instrumental or vocal timbres (Ashley, Reference Ashley, Fabian, Timmers and Schubert2014) as well as timespans that begin with relatively predictable elements before becoming more variable and then more predictable once more (Ashley, Reference Ashley, Fabian, Timmers and Schubert2014; Danielsen, Reference Danielsen2006).
The flux of fixedness and variability serve to differentiate individual performers' actions from one another and the sounding whole. Individuals' contributions may be detected from: chorusing, or not-quite unison in some musical line; distinctive timbres or musical figures identifying individual, discrete “sound sources”; and asynchrony in attack or spectral evolution, where joint action does not completely efface minute, audible differences between performers' actions. The ways in which performers are asynchronous with one another has been theorized as “participatory discrepancies” (Keil, Reference Keil1987) and proposed as fundamental to emergent groove. Such divergences from synchrony are additional instances of “levels of rhythmic complexity and expectation violation,” albeit at a “microtiming” temporal level which is faster than that of musical notation. Performance, in addition to composition, creatively and continuously modulates music as auditory display, with the actions and interactions of performers both predictable and unexpected – essential to groove and musical engagement beyond groove. There's a reason why we speak of “playing” music: it captures the nature of creative action between individuals well.
And so, I turn again to some suggestions of parallels between music and play. The social/group outcomes in Savage et al.'s framework parallel those proposed by researchers studying social play in nonhuman species. Theories of the origins and functions of animal play are varied (Bekoff & Byers, Reference Bekoff and Byers1998; Burghardt, Reference Burghardt2005) and our consideration here is, perforce, limited. We note that nonhuman species' actions in social play have been proposed as social bonding mechanisms (Bekoff, Reference Bekoff1984). One prominent theory of Spinka, Newberry, and Bekoff (Reference Spinka, Newberry and Bekoff2001) draws intriguingly close to Savage et al.'s framework, proposing that social play in animals trains organisms for responding to the unexpected. In playful interaction, animals find themselves not in complete control and so Spinka and colleagues propose that play “enhances the ability of animals to cope emotionally with unexpected situations,” is “emotionally exciting … and rewarding, maybe even pleasurable, while at the same time being relaxed … producing the complex emotional state that is referred to as ‘having fun’ in human folk psychology.” Finally, they consider play a “cognitively demanding activity” which “requires frequent and rapid assessment and reassessment of qualitatively different situations” (pp. 144–145). These descriptions fit human musicking as well as they do animal play.
Although one may seek insights into evolutionary processes by comparative studies, it seems well to conclude by connecting human play to musicking. A recent review proposes that “What might be distinctive about human play is that people not only exploit their existing knowledge about how to explore … but also explore new ways to explore” (Chu & Schulz, Reference Chu and Schulz2020, p. 332). The myriad ways humans have made, and continue to make, so many kinds of music from a handful of common starting points richly testifies to such explorations.
Financial support
This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Conflict of interest
None.