This article explores some key aspects of the early development of twelve-tone music in South America, from the 1930s to the end of the 1950s. Starting from the assumption that there is no such thing as "The Twelve-Tone Music" in capital letters, but that the use of this method has to be understood in every particular context, the history of the first centers of the creative reception of the twelve-tone method in South America is studied: the project of Nueva Musica in Buenos Aires, the group Musica Viva in Rio de Janeiro and Sao Paulo, and Tonus in Santiago de Chile. They were constituted by composers and interpreters dedicated to the composition and diffusion of twelve-tone music, and functioned as spaces of exchange, creation, and discussion. As I will propose, the networks among South-Americans, and between South-Americans and people of other countries as well, were fundamental for the development of the South-American twelve-tone music from its beginnings.