This study analyzes Urai Sikerai music and Turuk Sikerai dance as semiotic and performative constructions within the Mentawai indigenous community. Drawing on the paradigms of ethnomusicology and cultural semiotics, this article positions ritual music not merely as artistic artifacts but as cultural texts that mediate the relationship between humans, ancestors, and the taikabaggek spirits that regulate the balance of the Mentawai cosmos. The research employed a qualitative approach through participant observation and semi-structured interviews. Findings indicate that the musical structure of Urai Sikerai is constructed by repetitive formulas that serve to reinforce a liminal state, while the Turuk Sikerai dance emerges as a representation of the body-spirit negotiating the collective identity of the indigenous community. Through a Peircean semiotic framework and grounded ethnography, this study concludes that Sikerai music and dance serve as epistemic mechanisms that reproduce local Mentawai knowledge and simultaneously serve as symbols of cultural resistance within the context of modernity.