Peter Serkin and Richard Goode opened and closed Saturday night's Kennedy Center Chamber Music Society with the music for two pianos. This was especially heartening coming just a couple of weeks after a weekend when two sets of duo-pianists played concerts here. If this is a trend, may it prosper!

The Serkin-Goode closer was far more effective than their opener. Mozart wrote his C Minor Fugue, K. 426 for two pianos, later transcribing it for strings. On Saturday night it was unmistakably clear, even to one who likes Mozart on today's large grand piano, that several basic problems could not be overcome.

Mozart's superb, tightly woven, chromatic harmonies sounded muddied by the big pianos in the large hall. In a smaller hall with less need for strong projection, they might work. The performance was flawless, but the music was lost.

Ravel's own arrangement of his brilliant orchestral ballet, La Valse, was a very different matter. Goode and Serkin played with every desirable nuance in tempos, giving the great explosion shots toward the end immense excitement and filling the hall with sensuous sweeps along the way. No wonder the audience demanded and received an encore.

Further thoughts about the Concert Hall impeded on the Beethoven Cello Sonata in A Major played by Serkin with Leslie Parnas. Heard six days earlier in the Terrance Theater, it had been utterly clear in a powerful performance by young Colin Carr. On Saturday night, the large hall often swallowed up details in the cello part in spite of Parnas' complete technical command of the music. He and Serkin made the finale a moment of unusual strength.

Much of the most dazzling playing of the evening came when violinist James Buswell joined Serkin and Parnas in the C Major Trio by Brahms. The quality of their pianissimo playing in the scherzo was something rarely heard from any players, their Hungarian flair in the preceding movement a joy, and the finale a gathering together of inspired musicians.