We believe that music, as a model system of culture, offers a time-sensitive lens into the interplay between instrumental and ritual stances in cultural evolution. Music perception and production has been posited as a real-time, flexible form of creativity (Loui, Reference Loui2018). As such, musical experiences can switch between pursuing and not pursuing an end goal. Musical actions can present a causal opacity that is at times resolvable, and at times unresolvable. With these fluctuations come changes in the motivational structures that drive innovation and tradition.

These motivational shifts unfold at various timescales. At the slowest timescale, consider the decades-long evolution of musical styles. Take jazz music: Rhythmic syncopation and the use of swing tempo are hallmarks of jazz. This signaling may have arisen from a causally transparent goal to create variation from its predecessor of ragtime, such as by Morton's re-recording of Joplin's “Maple Leaf Rag” (Temperley, Reference Temperley2004), which activated the instrumental stance. In the hands of a modern jazz performer, however, swing and syncopation are automatically adopted, or copied with high fidelity from “the greats” during jazz instruction. The use of syncopation and swing can be seen as ritualistic, as they are normative articulations of action sequences that signal one's membership as a jazz musician, as opposed to, for example, a classical musician. Here, over the course of decades, the shift from instrumental to ritual stances drives the production of music from innovation to cultural evolution.

At a faster timescale, social interactions in music-making unfold on the order of minutes. Many experiments in music cognition have shown that a few minutes of moving in rhythmic synchrony with a partner leads to more prosocial behavior in children and adults (Cirelli, Einarson, & Trainor, Reference Cirelli, Einarson and Trainor2014; Hove & Risen, Reference Hove and Risen2009; Kirschner & Tomasello, Reference Kirschner and Tomasello2010; Rabinowitch & Meltzoff, Reference Rabinowitch and Meltzoff2017; Stupacher, Witek, Vuoskoski, & Vuust, Reference Stupacher, Witek, Vuoskoski and Vuust2020; Tarr, Launay, & Dunbar, Reference Tarr, Launay and Dunbar2016). Applied to bifocal stance theory (BST), moving in time entails action sequences that activate the ritualistic stance, supporting social bonding (Savage et al., Reference Savage, Loui, Tarr, Schachner, Glowacki, Mithen and Fitch2021). At an even finer timescale, the brain generates predictions that are continually tested with millisecond accuracy by incoming events on the musical surface (Vuust, Heggli, Friston, & Kringelbach, Reference Vuust, Heggli, Friston and Kringelbach2022). The dopaminergic system relates musical sounds to reward by learning from the systematic fulfillment and violation of these predictions (Salimpoor, Zald, Zatorre, Dagher, & McIntosh, Reference Salimpoor, Zald, Zatorre, Dagher and McIntosh2015). Thus the acoustic and statistical properties of music help minimize prediction errors, freeing up attentional resources to be directed toward specific gestures embedded in observed actions, and activating more “type 1 processing” in social learners.

Studying imitation versus innovation in musical interactions where goal-relevance is rigorously controlled could provide an excellent test model for BST. Each of the pathways of the cultural action framework depicted in Figure 3 of the target article could be probed by musical interactions with child participants. For the first row, in which no end goal is present, children could enter a room with a drum, sitting across from an experimenter drumming a rhythmic pattern followed by pauses during which the child could join in. For the fourth row, in which the end goal is present, but causally opaque and unresolvable, children could be expressly told when they enter that they are trying to play a rhythm that will make a set of puppets dance. The experimenter would play the rhythmic pattern, after which a second, unseen experimenter would make the puppets move in a different rhythmic pattern. Again in this situation, the prediction would be that children's drumming would show high levels of exact copying of the rhythmic pattern drummed by the experimenter. For the second and third rows, the children would once more be expressly told that their goal is to play the rhythm that makes the puppets dance. But in the case of the third row, where the causality is opaque but resolvable, when the experimenter's drumming stops, the puppets will dance in the same rhythm as had just been played on the drum, rendering the relationship resolvable. The child could extrapolate the relationship between drumming and dancing to conclude that the puppet would move to whatever rhythm they play, resulting in more novelty and less copying in their own drumming pattern. In the case of the second row, the relationship between drumming and dancing would be made causally transparent by the puppets moving once per strike to the experimenter's drumming pattern as it is played. Here, the prediction is that children, fully aware of the mechanics of the interaction, would explore more with novel drumming patterns.

What makes music an especially useful domain within which to explore switching between the ritual and instrumental stance is that copying is a highly common, ecologically valid mode of interacting musically; music is characterized by more repetition at more different levels than speech (Margulis, Reference Margulis2014). Musical behaviors can be explored not only in the context of production, as in the examples above, but also in the context of perception. In the case of perception, copying behavior may consist of listening and relistening to the same song or exploring new ones. Consider the listening behaviors that adolescents adopt when they see their friends listening to certain songs outside the context of a specific end goal, versus when one is clearly present: Listening to hype themselves up for a party that night, or to increase focus during studying, or to help them lift heavier weights at the gym. The first case might inspire the teenager to cue up their friend's specific songs, whereas the latter ones might yield a wider range of choices, involving the exploration of new playlists designed for a similar function.

Makers and consumers of music with expressly functional roles – aiding relaxation, soothing infants, rallying troops – may adopt an instrumental stance when using it toward an end goal. In contrast, people who download and listen to the same music may not be able to resolve its causal mechanism. Thus, they may view it instead from the ritual stance, motivating the “copy all, correct later strategy” of overimitation.