Banda is a rural Mexican brass band genre from the state of Sinaloa that became popular among immigrant populations of Los Angeles in the 1990s. In contemporary banda, the tuba has acquired a more prominent role than it held in traditional banda. The tuba has shifted from the traditional background harmonic and rhythmic function to a significant and new placement with the front line melodic instruments. The focus on tubas in modern incarnations of banda has helped it become a staple in acoustic and accordion genres such as sierreña and norteña. In many Mexican-American regional ensembles, the prominence of the tuba and its placement within the group represents a shift in its cultural significance, a stronger connection to the Mexican history and cultural roots, in the Mexican-American music community of southern California. This paper uncovers some of the motives and significance behind these recent changes in the role of the tuba in Mexican-American regional genres as well as the cultural connection that the tuba provides for Mexican-Americans in southern California to traditional Mexican music culture.