In the newly fluid territory between jazz, rock, performance art, and the avant-garde in the late 1960s, members of the Groupe de recherches musicales (GRM) in Paris initiated experiments in improvised electronic music. This article focuses on two iterations of a group centred on Alain Savouret, Pierre Boeswillwald, and Christian Clozier, who were either students on the GRM’s 1968 course at the Paris Conservatoire or researchers at the GRM. The article follows the group’s development from a practice of ‘live musique concrète’ with hand-built electroacoustic devices, tape effects, and synthesizers to a pluralist improvisation that engaged collaborators from free jazz and European and non-European folk traditions. This history results in two lines of argument: the first concerns the relationship between new electronic instruments and new modes of performance around 1970, while the second concerns the promise of electronic music as the site of a cross-cultural fusion of genres and traditions.