For five decades, Claudie Marcel-Dubois and Maguy Andral, key figures in ethnomusicology at the Museum of Popular Arts and Traditions, collected study material of great diversity, addressing musical practices and organology on almost all French territory, including some overseas territories. On the eve of reopening its collections in Marseille, the Museum of Popular Arts and Traditions (renamed MuCEM in 2005) launched a vast operation to safeguard the archives. The article sheds a particular light on the ethnomusicological archives which figure prominently in these collections. Thanks to a partnership between the National Archives, a team from the IIAC (CNRS-EHESS Anthropology Laboratory) and MuCEM, the digitization of the written archives, photographs and sound recordings is nearing completion and will soon be accessible on the Internet. The dematerialization of an unrivaled collection for ethnomusicology in France opens a broad range of new possibilities for examination and interpretation.