Many features of music contribute to its positive potential for promoting social harmony. But music’s influence on human interaction is not entirely benign. I consider features of music that enable it to serve such contrary projects, beginning by itemizing some of the mechanisms through which music creates feeling of solidarity among people. The very mechanisms that enable music to create solidarity can solidify bonds within sectarian groups that identify themselves in opposition to non-members. Music can also incite action because it activates the motor system, and when channeled into serving a propagandistic aim, it can promote action in the direction that has been cued. Because music entrains people rhythmically, it motivates acting in tandem, potentially fostering unquestioning allegiance to a cause. I go on to suggest four strategies for utilizing music to advance peace and other humanizing ends. First, efforts should be made to promote engagement with music that helps develop receptivity, empathy, and other peacebuilding attitudes and skills. Second, music education should make efforts to pre-empt the tendency to identify music with “us” or with “them.” Third, opportunities should be created for people to engage in “participatory performance,” which can transform people from relative strangers into shared musical participants. Fourth, musical hybridization, in which elements of diverse kinds of music are utilized in new musical forms, should be fostered. Music can demonstrate that engaging in creative and expressive activity with others can be enhanced, not diminished, by interaction with those outside one’s in-group, but we need to create the circumstances in which this can happen.