A survey of ethnomusicological studies of traditional cultures from around the world shows that, although the specific functions attributed to music are diverse, a common thread is that they involve connecting us to our environments: social, physical, and/or metaphysical. After proposing this as a definition of musicking, I consider this phenomenon in the context of the work of Maturana and Varela (the Santiago theory of cognition) and their successors. Human musicking can be understood as continuing the development of processes essential to all living things in their interactions with their environments, in other words, as an emergent property of life itself. Beginning with the ideas of autopoiesis, cognition and structural coupling, the Santiago theory explains that, with a sufficiently complex nervous system, organisms such as ourselves “bring forth” an interior world, and integrate or connect it with the external world that we bring forth through our senses. The nervous system, functions to integrate the brought forth worlds of all the living cells in our bodies. Musicking, because it engages sense (auditory perception), motor activity (sound production, entrainment) and our interior states (thought and emotion), appears to be an effective behavior in support of this integrative process; recent findings in neuroscience indicating the scope of connected brain activities in musically engaged subjects also support this idea. Furthermore, the often-noted effects of social cohesion and integration through musicking suggest the possibility, if we allow that social units might be understood as third-order autopoietic unities, that musicking has an important role at that level as well. Thus, we may be able to explain the awareness expressed in traditional cultures that music is essentially connective, as mentioned above, on the basis of contemporary understanding of the biology of cognition.