For one hundred years and more, musicians have been drawn to the potential of musical processes and relationships to embody democratic principles. This book is the first extended study of this ‘musical modelling of democracy’, as manifested in modern and experimental music of the global North. Four different approaches are surveyed in turn. In the music of Elliott Carter, democratic principles shape the textural relationships inscribed in the musical score. The indeterminate music of John Cage and his associates sought to democratise the composer–performer relationship by leaving open fundamental decisions about the realisation of a piece. Musicians have involved audiences in active participation, as a means to liberate them from a passive spectatorship. Free improvisation groups have experimented with new kinds of egalitarian relationship between ensemble members, in an effort to reject old hierarchies. In examining these different approaches, modern democratic theory is deployed to illuminate the achievements and ambiguities of musical models of democracy, stressing the heterogeneity of democracy as a concept, and the impossibility of conceiving specific democratic arrangements independently of particular, situated interests. An opening chapter establishes the contestability of democracy as a concept, and the book closes with a consideration of musical treatments of democracy in the age of Donald Trump.