A border can be represented by a line. But it can also be viewed more expansively, as its own space, fertile with the potential for either confrontation or learning and evolution. This study examines ways that music and dance can engage cultures across borders, in the absence of a common spoken language. Focusing on Translucent Borders, a three-year investigation at New York University, we consider various uses of improvisation at points of cultural juxtaposition. Translucent Borders is a project exploring ways that dancers and musicians act as catalysts for creative engagement across geographic and cultural borders. Beginning in refugee camps in Lesbos in 2016, Translucent Borders has facilitated global conversations between dancers and musicians in Israel, Palestine, Greece, Cuba, and Ghana through interviews, knowledge-sharing circles, improvisation, and performance. The project is a Working Group of NYU’s Global Institute for Advanced Study. In June, 2018, the world master dancers and musicians with whom the project has been working will come to the United States for a series of encounters resulting in world premiere performances at the Jacobs Pillow Dance Festival, Lincoln Center, and New York University. This paper articulates some of the inherent tensions in the use of improvisation over the course of the project and the performances in June. For instance: bringing together composers who use written notation, with master musicians who work primarily in a non-notational environment, can raise many challenges to both representative contingents, not just in the various aspects of sound production, but psychologically and territorially.