In The Soundscape, R. Murray Schafer describes a tone of 'prime unity', a tonal centre conditioning an international sonic unconscious. Diverging from the bucolic image of nature readily associated with Schafer's ethics and aesthetics, this tone is found in the ubiquitous hum of electrical infrastructure and appliances. A utopian potential is ascribed to this tone in Schafer's writing whereby it constitutes the conditions for a unified international acoustic community of listening subjects. This article outlines Schafer's anomalous concept of the tone of prime unity and interrogates the contradictions it introduces into Schafer's project of utopian soundscape design. Discussion of the correspondence between Schafer and Marshall McLuhan contextualises and identifies the source of Schafer's concept of the tone of prime unity. Of particular interest is the processes of unconscious auditory influence this concept entails and its problematic relation to the politics of sonic warfare. Through discussion of contemporary artistic practices that engage with these problems, it is argued that the tone of prime unity nonetheless presents an opportunity to shift the focus of Schafer's project from a telos of divine harmony towards collective self-determination through participatory intervention in the world around us.