The countries of Latin America have long been recognized as containing rich holdings of primary sources for music, but access to them and detailed knowledge of their contents has sometimes been difficult to obtain. However, a number of efforts in recent years to promote these collections have increased their visibility. IAML approved a national branch in Brazil in 2014, and RISM has scholars in both Brazil and Mexico who are working on curating collections. The speakers of this plenary session will provide an overview on several projects that involve cataloging and promoting music special collections in these two countries. Yael Bitrán Goren is the Director of the Centro Nacional de Investigación, Documentación e Información Musical “Carlos Chavez” (CENIDIM) in Mexico City. The CENIDIM holds a number of special collections and is responsible for cataloging, preserving, and digitizing materials. Yael will select two or three collections and discuss the work that CENIDIM has done with them. André Guerra Cotta is Associate Professor at the Universidade Federal Fluminense Polo Rio das Ostras in Rio de Janeiro and will be presenting on two special collections, Mariana’s Museum of Music and the Curt Lange Archive. Beatriz Magalhães Castro is President of IAML-Brazil; she will give an overview of IAML’s work in her country as well as strategies for future developments.