In Los Angeles during the early 1940s, the popular music and dance performances of a cross-cultural swing scene provoked reactionary regulation by white urban elites and law enforcement authorities. Reacting to multiracial musicians, dancers, and entrepreneurs, local politicians and municipal arts administrators created a Bureau of Music in order to encourage patriotic citizenship, prevent juvenile delinquency, and bring proper music to the people. This article argues that successive generations of Angelenos defied the city's rule of racial separation and white domination, creating a multicultural urban civility as they intermingled in dance halls, ballrooms, and auditoriums. Despite personal prejudice and internalized racism within and between different groups, dance music facilitated intercultural affinities that went beyond mere politeness or courtesy to include respect and tolerance. In diverse but distinct music scenes, Angelenos sustained egalitarian social relations in the face of blatant attacks on their civil liberties, particularly the right to freedom of assembly in public spaces. Ultimately, the educational infrastructure, cultural production, and grassroots initiatives of musicians, promoters, and fans brought music to more people, and brought more people from different neighborhoods together, than the official middle-class music programs of the city government did. Through cultural creativity and entrepreneurial activity, the irrepressible swing and RandB music scenes resisted social segregation and highbrow reification by fostering contact and comprehension, as well as musical and physical expression. Shaped by the influence of African Americans and Mexican Americans, the region's two largest racial minorities, the culture wars of the 1940s and 1950s illustrate how power struggles over public space, common values, and a democratic American culture played out in popular music and dance venues.