Scientists, their allies, and opponents engage in struggles not just over what is true, but who may validate, access, and engage contentious knowledge. Viewed through the metaphor of theater, science is always performed for an audience, and that audience is constructed strategically and with consequence. Insights from theater studies, the public understanding of science, and literature on boundary work and framing contribute to a proposal for a framework to explore the construction of audiences during scientific controversy, consisting of three parameters: history, composition, and role. Applying this framework to the controversy over the presence of genetically modified maize in Mexico demonstrates how multiple and contested audiences form during a scientific controversy. Different scientific “productions” construct distinct or overlapping audiences; audiences constructed at one time become “easy recruits” for later stages of the controversy; and the various roles cast for different audiences showcase strategies for building scientific power and reflect assumptions about the capacity for publics to participate in the governance and production of science.