Trio Mexico, an ensemble founded in 1975, performed an interesting concert Monday night at the Kennedy Center Terrace Theater. Playing with spirit and a good degree of musical freedom, violinist Manuel Suarez, cellist Ignacio Mariscal and pianist Jorge Suarez were presented as part of the center's International Chamber Music and Recital Series.

The Trio in D minor, Op. 54, by the versatile contemporary British composer Malcolm Arnold was approached with vigor and an appreciation for the music's fine instrumental writing. The open sound of the strings in the allegro, the andante's sweet keyboard melody and the frantic quality of the closing vivace all received close attention. Overall, the group showed a gratifying understanding of this attractive work.

A piece by the 20th-century Mexican composer Mario Kuri-Aldana (the program indicated it was "Sonatina Mexicana" for violin and piano, although all three musicians played throughout the work) created a lilting stream of folk-inspired melodies. Some uncertain intonation crept into the three movements, but the simple and warm flavor of the music stood unaffected by any technical lapses.

One of the most familiar piano trios in the literature, Schubert's Trio in B-flat, Op. 99, was also a bit weak in some stricter aspects of ensemble and intonation. However, the musicians were eager to provide bright, flexible phrasing in the buoyant themes, and they strove for a keener instrumental balance in the closing movements.