NOT MANY native musics in the Western Hemisphere survived the onslaught of European colonization. Up in the high peaks of the Andes, though, a vibrant folk music tradition has survived and thrived, preserving a sound quite different from the African and European music that now dominates this hemisphere.

Andean folk music sounds quite different from anything else: The wooden pan pipes create a breathy, ethereal quality; the wooden drums anchor the music with patient, echoing beats; the guitars adapted from the Spanish colonists imitate the overlapping, rising-and- falling melodies of the pipes.

Two Bolivian emigres in Washington, Carlos Arrien and Alvaro Encinas, are the core of Rumisonko. The group's first album, "El Huerto/The Backyard," alternates effectively between Encinas' virtuoso guitar work on enchanting instrumentals and Arrien's pointed political vocals on the songs.

The album's biggest asset is its understatement: Encinas favors subtle, restrained passages over flashy fretwork; Arrien's lyrics attack imperialism not with slogans but metaphors taken from nature.

Perhaps the best known Andean folk group is Inti-Illimani, made up of six Chilean political exiles now living in Italy. Its newest album, "Imagination," is a superb collection of instrumental works from the Andean folkloric movement. Three guest artists join the sextet for chamber arrangements played with a classical musician's precision and a folk musician's enthusiasm.