In this article, the author offers an overview of her experiences in developing the GRM’s Portraits polychromes, a series of books associated with multimedia documents presented on the Internet site of the GRM since 2001. In releasing this collection, the concern was to increase awareness of the electroacoustic repertoire and the reserves in the GRM archives. At present, the catalogue contains around 2,000 works, accompanied with supplementary documents: composer’s biographies, reviews, photographs, documentary movies, radio broadcasts, recorded public lectures, theoretical research work, transcriptions and analyses. In addition to the heritage value of the GRM’s collection, the enterprise of the Portraits polychromes, with the aid of multimedia tools, aims to advance the progress of research on analysis and the transcription of musical works. The multimedia transcriptions, produced within the past four years for Portraits polychromes, explore different methods of analysis and transcription. Transcriptions can have several functions, such as being used as a working draft, a basis for analysis, or even an object of analysis, a guide to interpretation, a pedagogic tool to help reveal the work to music lovers, and even provide a medium for working out creative ideas.