Is our capacity to synchronize our musical behaviours with others. This may be by performing the same action at the same time (e.g. clapping or chanting in unison–synchronization sensu strictu) or various more complex forms of entrainment such as antiphony or the complex interlocking patterns of an agbekor drum ensemble. Although solo music, performed by a single individual, is not uncommon, music performed in groups is a far more typical expression of human musicality. This is again a universal behaviour seen in at least some of the music of all human cultures [60], and such coordinated group displays also find important parallels in the animal world. Social synchronization requires individual capacity for synchronization to some external time-giver. The most sophisticated form of synchronization involves beat-based predictive timing, where an internal beat is tuned to the frequency and phase of an isochronous time-giver, allowing perfect 08 phase alignment. This capacity to extract an isochronic beat and synchronize to it is termed `beat perception and synchronization’ or BPS [94]. Although the majority of research in both humans and animals studies BPS to either a metronome or recorded musical stimuli [95,96], human rhythmic abilities obviously did not arise to allow people to synchronize to metronomes, but rather to the actions of other humans, in groups. Thus, by the ecological principle, the concept of `mutual entrainment’ among two or more individuals should be the ability of central interest, rather than BPS to a mechanical timekeeper. Despite a long tradition of suggesting that BPS is uniquely human, recent findings clearly document this ability in several species, including many parrot species [97?9] and more recently a California sea lion Zalophus californianus [100]. By contrast, the evidence for BPS in non-human primates remains weak, with partial BPS by a single chimpanzee and not others [101]. Thus, the existing literature suggests a lack of BPS abilities in other non-human primates (see Merchant et al. [10], and [102?04]). Thus, while human BPS clearly finds analogues in the animal kingdom, it is too early to say whether homologous behaviours exist in our primate relatives. But again this aspect of human musicality provides ample scope for further comparative investigation (cf. [105]). Synchronization in larger groups–`chorusing’–is also very broadly observed in a wide variety of non-human species, including frogs and crickets in the acoustic domain and fireflies and fiddler crabs in the visual domain (for ARQ-092 chemical information reviews see [37,40]). In some cases choruses involve BPS. For example, in certain firefly species, all individuals in a tree synchronize their flashing to produce one of the most impressive visual displays in the animal kingdom [106?08]. These cases all represent convergently evolved analogues of BPS, and thus provide ideal data for testing evolutionary hypotheses about why such synchronization capacities might evolve, along with mechanistic hypotheses about the minimal neural requirements supporting these capacities. Although frog, cricket and firefly examples areoften neglected in discussions of music evolution, presumably because they are limited to a particular signalling Torin 1 msds dimension and a narrow range of frequencies, there are some species which show a flexibility and range of behaviours that is musically interesting. For example the chirps of tropical Mecapoda katydids are typically synchronized ( predictively e.Is our capacity to synchronize our musical behaviours with others. This may be by performing the same action at the same time (e.g. clapping or chanting in unison–synchronization sensu strictu) or various more complex forms of entrainment such as antiphony or the complex interlocking patterns of an agbekor drum ensemble. Although solo music, performed by a single individual, is not uncommon, music performed in groups is a far more typical expression of human musicality. This is again a universal behaviour seen in at least some of the music of all human cultures [60], and such coordinated group displays also find important parallels in the animal world. Social synchronization requires individual capacity for synchronization to some external time-giver. The most sophisticated form of synchronization involves beat-based predictive timing, where an internal beat is tuned to the frequency and phase of an isochronous time-giver, allowing perfect 08 phase alignment. This capacity to extract an isochronic beat and synchronize to it is termed `beat perception and synchronization’ or BPS [94]. Although the majority of research in both humans and animals studies BPS to either a metronome or recorded musical stimuli [95,96], human rhythmic abilities obviously did not arise to allow people to synchronize to metronomes, but rather to the actions of other humans, in groups. Thus, by the ecological principle, the concept of `mutual entrainment’ among two or more individuals should be the ability of central interest, rather than BPS to a mechanical timekeeper. Despite a long tradition of suggesting that BPS is uniquely human, recent findings clearly document this ability in several species, including many parrot species [97?9] and more recently a California sea lion Zalophus californianus [100]. By contrast, the evidence for BPS in non-human primates remains weak, with partial BPS by a single chimpanzee and not others [101]. Thus, the existing literature suggests a lack of BPS abilities in other non-human primates (see Merchant et al. [10], and [102?04]). Thus, while human BPS clearly finds analogues in the animal kingdom, it is too early to say whether homologous behaviours exist in our primate relatives. But again this aspect of human musicality provides ample scope for further comparative investigation (cf. [105]). Synchronization in larger groups–`chorusing’–is also very broadly observed in a wide variety of non-human species, including frogs and crickets in the acoustic domain and fireflies and fiddler crabs in the visual domain (for reviews see [37,40]). In some cases choruses involve BPS. For example, in certain firefly species, all individuals in a tree synchronize their flashing to produce one of the most impressive visual displays in the animal kingdom [106?08]. These cases all represent convergently evolved analogues of BPS, and thus provide ideal data for testing evolutionary hypotheses about why such synchronization capacities might evolve, along with mechanistic hypotheses about the minimal neural requirements supporting these capacities. Although frog, cricket and firefly examples areoften neglected in discussions of music evolution, presumably because they are limited to a particular signalling dimension and a narrow range of frequencies, there are some species which show a flexibility and range of behaviours that is musically interesting. For example the chirps of tropical Mecapoda katydids are typically synchronized ( predictively e.