The Catholic University Orchestra provided a tour of Latin American music Wednesday night at the Organization of American States. Even with obvious omissions, there was much evidence of where Latin American music has been and, because of the presence of a young Argentine composer, where it might be going.

Beginning with the 19th-century Brazilian composer Antonio Carlos Gomes, the orchestra, under the direction of Robert Ricks, played the Overture to "Il Guarany," a pastiche of Italian-German-Spanish operetta music. This was followed by the "Toccata for Percussion" of Mexico's Carlos Chavez. After almost half a century, it is still daring, using thematic rhythms but wonderfully conveying line and form in its three movements.

The familiar "Bachianas Brasileiras No. 5" of Villa-Lobos fared poorly in that echo-chasing hall, meeting itself at every turn. But it is still a novelty for the audience, hearing the soprano soloist accompanied by an "orchestra" of eight cellos.

"Alas Ala," by the young Argentine Guillermo Silveira, is in truth a theater piece, based on a poem by Jorge Luis Borges. The piece is written for clarinet, piano, mixed percussion, cello, two narrators -- one in Spanish, one in English -- and a wordless women's chorus that also whistles. The poem, consecutively recited in two languages, speaks of the age-old barrier between humans, the Cain-Abel relationship. Silveira puts text first; musical sounds ornament the words. It is dramatic and effective, and it, too, suffered from the ripple effect of the hall's echoes.

The program ended with the finely wrought "Variaciones Concertantes" of Alberto Ginastera.

The concert came from Catholic University's Latin American Center for Graduate Studies in Music, whose effort and purpose must be applauded. One hopes, however, that in the future program notes will be provided for unfamiliar territory.