Henri Lazarof's String Quartet in Three Movements, which had its world premiere last night at the Organization of American States, is a technically brilliant, emotionally intense work by a composer who has mastered every expressive resource of the string quartet medium.

It is compact music, highly energetic, mercurial--packed with melodies that dance at the edge of tonality and range in mood from deep solemnity to dazzling cascades of glittering sound. It is a worthy addition to the distinguished list of premieres presented by the Inter-American Music Festival in its 25-year history, and it received a performance fully worthy of its craftsmanship.

Members of the Los Angeles Contemporary Music Ensemble--violinists Yukiko Kamei and Darius Campo, violist Milton Thomas and cellist Gabor Rejto--made this new music sound like the familiar classic it should become.

It was the final work and the climax of a program that set high standards throughout, both in repertoire and in performance, despite last-minute changes caused by the illness of pianist Eduardo Delgado. Substituting for him on a few days' notice, Kazamo Hayami participated in every work on the program except Lazarof's Quartet and performed solo in "Jazz Elements" by Meyer Kupferman, which replaced four short Argentinian pieces. Within a basically 12-tone structure, this work hints at jazz idioms that range from cocktail-lounge piano through Gershwin-like harmonic progressions to fragmented motifs with characteristic cadences of Duke Ellington's melodies. Kupferman is a jazz pianist seduced by the techniques of Arnold Schoenberg, and his music clearly identifies him as such.

The program opened with Kamei and Hayami playing "Vino" by Robert Linn, a "1975 vintage" work composed in the California wine country. In his program notes, the composer says he hoped to make it "a bit intoxicating to the senses, transparent in texture, clean in form with good body and color, and not too dry." The description is precise.

Two of Latin America's leading contemporary composers rounded out the program: Camargo Guarnieri of Brazil, whose warmly lyric Sonata for Viola and Piano was beautifully played by Thomas, and Alberto Ginastera of Argentina, whose brilliant "Pampeana No. 2" was explored in every dazzling nuance by Rejto.