Cultural and geographic regions offer ways to explore spaces that do not always coincide with state boundaries. Mountains, coasts, valleys, and exchange corridors connect communities and facilitate the movement of musicians, instruments, and repertories. In Mexico, one tradition may extend across several states while very different practices coexist within a single region. This section gathers broad territorial categories for comparative browsing. Regional location guides a search, but cannot by itself establish a recording’s language, community affiliation, or social function.