The zeal for ‘modality’ in French modernist composition drew sustenance from the Indo-European hypothesis (or ‘Aryan myth’) of a linguistic-turned-‘racial’ patrimony linking India, Greece, and Europe, prevalent in Francophone intellectual, including musicological, discourse. Against this backdrop, the central case study traces how the Karnatic melakarta system of rāga classification travelled from Southern India, via British imperial networks, to French universities and conservatoires, whereupon it found widespread interest among composers and pedagogues including Roussel, Emmanuel, Tournemire, and Dupré. Yet the melakartas’ enduring imprint upon French music is found not simply in the use of individual scales, but in the premise of a fecund ‘modal republic’, inspired by the system’s generative logic and resonant in the rationalized modalism of the 1920s and ’30s, including Messiaen’s ‘modes of limited transposition’. The article concludes by proffering a novel conceptualization of the entanglements between Karnatic and French scale systems (and epistemologies of music) in the early twentieth century.