Focusing on relations between two American ethnic groups which would seem not to have much in common, the Irish and the Jews, the essay explores a process of immigrant acculturation in the streets, through the city political machine, on the vaudeville stage, and in the music and performance between 1900 and the 1930s. Although Ireland was generally thought to be a tolerant society with regard to Jews, Irish American urban communities were often characterized by a degree of anti-Semitism. Irish gangs sometimes attacked Jews in the streets and some of the popular culture representations of the Jew propagated by Irish performers were derogatory. The Tammany machine in New York integrated Jews in an effort to hold their power base in the city, though anti-Semitism resurfaced among the Irish in the face of the Great Depression. Yet both vaudeville in the early twentieth century and the Tin Pan Alley music and films of the World War One era and the 1920s depicted sympathy, attraction, and even romantic love between the two groups. Relations between the two groups suggest the full range of possibilities - from violent confrontation in the streets to political competition and cooperation, from fictional representations of one another on stage and in song to romantic love and intermarriage. In their complexity and uneven quality, these relations helped to shape a new urban culture that was the creation not of one group or another but, rather, the product of inter-ethnic acculturation.