This article examines the previously unstudied history of Chicago’s nineteenth-century music saloons, tracing their development from transplanted German beer halls to Americanized entertainment resorts to commercial dance halls. Drawing on evidence from scattered newspaper sources, the article documents women’s ubiquitous presence in music saloons as waiters, performers, prostitutes, and patrons and then interprets what their presence reveals about the public role of women in nineteenth century American cities. The women in music saloons asserted considerable social freedom, articulated a public identity that emphasized sexual expressiveness, and helped create a morally ambiguous environment that defied the prevailing Victorian distinctions between respectable and disreputable. In doing so, they helped define what it meant to be a modern city girl. The article also examines the affect that municipal regulation had upon the operation of Chicago’s music saloons. City officials restricted the presence of music and women but only periodically enforced the restrictions. The sporadic enforcement never removed women or music for long but nonetheless structured the social and cultural environment of the city’s music saloons.