This article describes the ways in which music is an important part of identity, and hence serves some similar functions to other forms of identity-related communication (e. g., language). It will describe how music is used to incite intergroup hatred (e. g., among soccer fans, military music) and to support valued identities (anthems, etc.). Relevant literature on stereotyping (including stereotyping of groups related to music) is included. The article also discusses how music is used to reduce intergroup hostility (e. g., via cross-cultural musical collaboration and contact). The article connects the various literatures from communication, social psychology, sociology, and ethnomusicology, providing a broad overview of the many connections between communication, music, and social identity. It closes with a research agenda for those interested in studying intergroup communication and music.