This paper explores radio broadcasting and monitoring by and about SPLM/A leader John Garang de Mabior during the first half (1983-1991) of Sudan’s second civil war. It places Garang’s broadcasts in conversation with those of his critics—northern, southern, and international—to argue that ‘rivalry in the ether’ directly shaped the struggle for political authority between Garang and the Sudanese government, and within the SPLM/A elite. Although radio broadcasting is often studied in isolation from other forms of aural production, it also argues for the importance of studying clandestine broadcasting within a wider wartime soundscape, including government and international radio with which rebel broadcasts were in dialogue, as well as internal SPLM/A radio communication and revolutionary songs composed during the struggle.