The bandio williche is a culturally significant musical instrument played in the territories of Osorno and San Juan de la Costa, in the northern part of the present-day Los Lagos Region in southern Chile. The general objective of this study is to understand the musical communication processes that emerge from the performance of the bandio within the Mapuche Williche world of this territory. Theoretically, we propose a dialogue between sociocultural and musical research perspectives in order to approach the phenomenon from an interdisciplinary standpoint. Methodologically, our research strategy follows a case study design, drawing on and articulating information-gathering techniques such as bibliographic documentation, interviews, participant observation, and the auxiliary use of musical transcription. The results show how the bandio functions as a medium that participates in ritual and social communication processes, becoming a sign of territorial identity.