This chapter studies relations between Schoenberg, Stravinsky and their respective camps, from the early twentieth century through the composers’ later years in California. Beginning with an early moment in which their relations were characterized by curiosity and mutual respect, it sketches the emergence in the 1920s of an opposition between Schoenberg’s expressionism and Stravinsky’s neoclassicism. It then examines how this opposition was reinterpreted and codified (if not ossified) in T. W. Adorno’s influential Philosophy of New Music, and in his subsequent writings on both composers. Adorno described Schoenberg’s music as a seismograph that registers tremors of feeling; this chapter reworks Adorno’s metaphor in order to propose that the Schoenberg–Stravinsky–Adorno triad might register tectonic movements of a much larger modernity. Engaging with recent literature on all three figures, it suggests some ways their work might relate to modern regimes of racial difference.