This thesis explores the ontological grounds of the interrelations between music and myth among the Marubo, one of the several native peoples of the Pano linguistic family who live not far from the adventitious border between Brazil and Peru, in South Western Amazonia. The thesis lies within the disciplinary boundaries of social anthropology but, inasmuch as it focuses on myth and music, its theoretical and methodological limits overlap any discipline that may relate to these two themes. In brief, it portrays the Marubo as they express themselves and are themselves expressed in their saiti festivals and myth-chants. In their native language, saiti designates a specific festival where myths are performed in a specific musical and choreographic form, the form that establishes the ontological origins of these peoples and those of the world where they live.