Background: Art making is a personal and social process in which learners make meaning for themselves and audiences through the production of artifacts. In classrooms, this personal and social process is made concrete through dialogue. Methods: This paper presents an illustrative case study of how sixth-grade student, Jo, developed voice through interaction with peers in a classroom context while making art about social issues. Interaction analysis methods supported inquiry into Jo's talk about art making as she talked with peers in designed conversation spaces (i.e., intentional structures and opportunities to talk about artwork while making it). Findings: Jo's voice development illustrates the collaborative nature of voice as an interactional accomplishment; having a unique voice is something students might strive to achieve as artists, yet that voice is co-constructed through collective social interaction as students take up, appropriate, and build on others' ideas. Artistic and political dimensions of art making were generative. Contribution: Pedagogical implications are discussed for designing socially supported learning experiences in arts classrooms. What Jo's case makes evident is that voice can be supported in classrooms through intentional pedagogical choices that create the conditions for that voice to develop through interactions with peers and materials.