Though many pre-service music teachers have received exemplary instruction in their high school music programs, these programs may not be representative of the social, cultural, and economic diversity of their broader communities. This insularity may hinder their perceptions of their community as they step into an increasingly diverse school environment. The Champaign County Juvenile Detention Center (CCJDC) Arts Project was adopted as a critical service-learning course in order to introduce preservice music teachers to students and ways of teaching that may be different from what they typically encounter through their university field experiences. Participants in the project designed and facilitated music and arts experiences with the incarcerated youth once per week over an entire semester. In this case study we examine the experiences of six pre-service music teachers who participated in the CCJDC Arts Project during 2012, looking for moments of "dissonance," which Kiely defines as incongruities between participants' past experiences and the challenging reality they encounter through the project. Entry into the facility, interactions with the youth at the facility, and the musical practices shaped by the needs of the facility all worked in tandem to challenge participants' latent expectations and beliefs about their community, and to heighten their awareness of the sociocultural systems that shape their future students, their developing teaching practices, and their own privileged positions in school and society.