For all the performers, chorus, soloists, orchestra and conductor alike, getting through the Missa Solemnis by Beethoven must be like crossing the Rocky Mountains: you no sooner reach the summit of one great range when another appears in the distance, and it, too, must be overcome, before the relief of the Sanctus and Benedictus are reached.

Last night in the Kennedy Center Robert Shafer conducted the dreadful work in a way that evoked much admiration. The Oratorio Society, which is Shafer's creature, is faultlessly trained. They observed the many minute dynamic markings that fill the score; their enunciation was utterly clear, and their tone never failed in beauty despite the awesome demands made by the needless composer.

Indeed, if there were one element the chorus could have added to give the music greater impact it would have been for the men and women to let loose with some outright, full-throated volume at those points where Beethoven simply has to be shouted.

Shafer took the entire work with great deliberation, even in passages where Beethoven is shaking his fist in the face of God and men. Surely the fugues, "In gloria Del Patris" and "et vitam venturi" should move a bit more rapidly if they are not to wear out their welcome ahead of time. But the musicianship that underlay everything Shafer did was the clear result of long and insightful study.

Soloists in the Missa must be of operatic caliber, as they were last night. Lili Chookasian was a model of musical vocalism, inflecting the contralto solos with subtle beauties not often heard in the part. Tenor Gene Tucker was in fine voice and sang with his accustomed ease and style. Douglas Lawrence, the bass, was lofty while maintaining superb tone. Only soprano Marilyn Zschau missed most of her great moments. Though she produces some lovely sounds, she totally avoids singing woods, so that her "Kyrie eleison" sounded like one long "ah."

With the National Symphony in Japan and the Kennedy Center Orchestra busy with ballet, Shafer drew together an orchestra that was far too small, but in which were some of the city's best musicians. Jody Gatwood played the famous violin solo with exquisite tone, though it needs to speak out more. Had the organ been used with much greater freedom, the bass lines would have benefited greatly.