The 14th-century madrigal that introduced yesterday's Theater Chamber Players concert in the Terrace Theater contained the lines, "O music, thou my dear art . . . I am loyal to thee." It could have been the motto for the evening. From tenor James McDonald's exquisite shaping of the initial melodic flourish in the madrigal to the spirited finish of the second Brahms string quintet, the Theater Chamber Players were impeccable servants of music in one of their most mving programs to date.

The first half was devoted to works that delved into the deeper regions of the human spirit. Utilizing a text by Michelangelo, the Italian composer Girolamo Arrigo evoked the act of creation itself in his work, "Lo schiavo morente," for tenor and horn. McDonald and Robert Sheldon gave a performance of exceptional dimension, finding just the right disembodied quality for the opening section dealing with the spirit's agonies.

Another comtemporary Italian, Goffredo Petrassi, presented a powerful testimonial to Martin Luther King with his taut, sparse setting of the Beatitudes for baritone and small ensemble. Baritone Richard Frisch and the instrumentalists responded with expressive sensitivity to Petrassi's careful use of color and dissonance.

Culminating the spiritual searching of the first half was Bach's first sonata for unaccompanied violin, played with pure, flowing intensity by Pima Carmirelli.

Perfectly balancing the first section of the program was Brahms' second quintet for strings, an eloquent outpouring of the individual human heart.