How do outsiders negotiate participation within a subculture when they are deemed inauthentic by that subculture's insiders? To explore this question, I examine the underground hip-hop scene in Chicago. The insiders are black and Latino, male rappers from the city's urban core. The outsiders are white, female, and/or suburban rappers, who want to participate in hip-hop culture, but are deemed inauthentic by insiders. I demonstrate how, through cultural practices and a rhetoric of authenticity, the conditions that govern 'realness' and 'fakeness' are continually reshaped, on the basis of context. Exploring how this boundary work is utilized to create, maintain, and occasionally traverse race, gender, and class-based cultural boundaries, I underscore the flexible and varied uses of the authentic, a conceptual framework I label situational authenticity.