This paper explores how protest music both illuminates and consistently refracts Taiwanese national identity through the pop anthem “Island’s Sunrise,” which has mobilized across recent social movements. As an imagined state uneasy in hegemonic conceptions of nationhood, Taiwan has, over the past decade, witnessed the rise of grassroots protest movements responding to escalating interventions from China. Paradoxically, appeals to unity have intensified the historical precarity of this national identity. This paper examines the creation, enactment, and effects of “Island’s Sunrise,” outlining a semiotic analysis of the music itself alongside semi-structured interviews conducted with protester-musicians. Preliminary findings suggest that “Island’s Sunrise,” imbued with cosmopolitanism, interweaves verbal and nonverbal signs inherited from Taiwan’s serial colonial history. Building on Dylan Robinson’s concept of critical listening positionality, I decipher these signs through what I term post-serial-colonial listening in contemporary Taiwan, whereby the semiosis generates a political collective affect oriented toward Taiwanese sovereignty. Yet in practice, this song operates as a discordant semiotic mediator, revealing a peculiar double-edged force: for protester-musicians, it is powerful yet fragile, communicative yet prone to slippage, crafting collective belonging while cracking it from within. Across song-related multi-scalar episodes, it trumpets partisan tensions between pro-Taiwan and pro-China positions and, through its prohibition in China, reverberates conflicts between democracy and authoritarianism. Through “Island’s Sunrise,” this paper extends Thomas Turino’s framework to examine the generative dynamics of participatory music-making amid multidimensional political pressures, inviting a rethinking of music as carrying, at once, the potential of political mobilization and the conditions of its undoing.