This dissertation is an ethnographic and historical examination of Senegalese modern identity and cosmopolitanism through urban dance music. My central argument is that local popular culture thrives not in spite of transnational influences and processes, but as a result of a Senegalese cosmopolitanism that has long valued the borrowing and integration of foreign ideas, cultural practices, and material culture into local lifeways. My research focuses on the articulation of cosmopolitanism through mbalax, an urban dance music distinct to Senegal and valued by musicians and fans for its ability to shape, produce, re-produce, and articulate overlapping ideas of their ethnic, racial, generational, gendered, religious, and national identities. Specifically, I concentrate on the practice of black, Muslim, and Wolof identities that Senegalese urban dance music articulates most consistently. The majority of my fieldwork was carried out in the nightclubs and neighborhoods in Dakar, the capital city. I performed with different mbalax groups and witnessed how the practices of Wolofness, blackness, and Sufism layered and intersected to articulate a modern Senegalese identity, or Senegaleseness. This ethnographic work was complimented by research in recording studios, television studios, radio stations, and research institutions throughout Senegal. The dissertation begins with an historical inquiry into the foundations of Senegalese cosmopolitanism from precolonial Senegambia and the spread of Wolof hegemony, to colonial Dakar and the rise of a distinctive urban Senegalese identity that set the proximate conditions for the postcolonial cultural policy of Négritude and mbalax. Subsequent chapters focus on the practices of Wolofness, Sufism, and blackness articulated through mbalax.