Book excerpt: This volume examines the ontology of music groups. It connects two fascinating areas of philosophical research: the ontology of social groups and the philosophy of music. Interest in questions about the nature of music groups is growing. Since people are widely familiar with music groups, the topic is particularly well-suited for introducing issues in social ontology. Being comparably small-scale and temporary, music groups also provide an excellent case study for those who think that social groups are analyzed best by considering small groups. The present volume provides a comprehensive overview of the topic and seeks to establish the ontology of music groups as a distinct field of philosophical research. The chapters, written by leading scholars working on social ontology, revolve around four core themes: The identity of music groups Variations between different kinds of music groups The persistence and longevity of (different kinds of) music groups Various characteristics of music groups, including their rational and emotional aspects, as well as their creative abilities The contributors consider these themes across a wide range of music groups, including popular music groups, rock bands, alternative acts, hip hop crews, choirs and classical orchestras. The Ontology of Music Groups will appeal to scholars and advanced students working in social ontology, metaphysics, and the philosophy of music.