Debussy's "Pre'lude a l'apre s-midi d'un faune" is an orchestral tour de force that one suspects would not translate gracefully to the percussive language of the piano. But Debussy did make such a translation (and, later, so did Ravel) for two pianos, and in the right four hands, it is quite wonderful.

Pianists Edmund Battersby and Christopher O'Riley did the honors last night at the Library of Congress, pouring unusual care into the legato opening phrase, endeavoring to recreate orchestral accents and voice leading, and, most of all, nurturing the balance of colors and textures that makes this music so special. Their delicate effort was sandwiched between two more rollicking pieces, Milhaud's "Scaramouche" and Ravel's "La Valse," again an arrangement from the orchestral score. Both of these were great fun if not great music and O'Riley and Battersby attacked them with style and flair.

The first half of this all-French program focused on Ravel's splendid Sonata for Violin and Cello and Faure''s "La Bonne Chanson." Violinist Alexis Galpe'rine and cellist Carter Brey had rather different understandings of the Ravel. Galpe'rine took it on broadly and with an almost Baroque sense of line, while Brey's approach was tough and unyielding. Each has its own possibilities, but, together, there seemed to be more antipathy than agreement.

The evening's finest ensemble came in the Faure' song cycle, scored for piano, strings and mezzo-soprano. Constance Beavon has just the voice for this sort of French music, slightly husky, technically assured and comfortable in the range. A greater variety of vocal color and a lot more consonants would have made this an outstanding performance.