The twentieth century was a period of radical transformation in the materials, resources and technologies available for music. Pierre Boulez was at the forefront of these developments, yet at the same time he displayed a curious ambivalence towards them. This chapter shows how, as a powerful cultural figure committed to the project of modernity, Boulez embraced the technologies of the new age, particularly through his guiding of the programme of activities undertaken at the music/scientific research centre IRCAM, which he helped to found in Paris in the 1970s. It also shows how, in his own compositional work, he displayed an ambivalent and musically conservative attitude towards new technological developments, leaving the details to others, while maintaining a quite traditional view of musical composition and performance. The chapter explores the conceptual, historical and cultural contexts for Boulez’s engagement with technology, and examines some of the works he composed using the technological resources developed at IRCAM.