With American Ballet Theatre's second program at the Kennedy Center Opera House last night, one could begin to perceive more clearly, at least in outline, the kind of personal contribution Mikhail Baryshnikov hopes to make to the repertory in his new capacity both as artistic mentor and director of the troupe.

The evening began with a ballet by Michel Fokine, and ended with one by Marius Petipa, both of them in respectful retouchings by Baryshnikov. What we saw last night clearly bore the stamp of Baryshnikov's own hand, molded in turn by his upbringing with the Kirov Ballet of Leningrad.

It is Baryshnivkov's stated intention to purify such works, to restore them as much as possible to a pristine state, in respect to choreography and style, and bring them more into line with the Kirovian ideal as he knew it -- a compound of formal rigor, stylistic austerity and expressive refinement. He is, however, working with an American company, whose motley backround and experience is far removed from his own. The outcome, by the evidence of last night's program, is that there is much ground still to cover, but that a very impressive beginning has been made toward these goals.

"Les Sylphides," indeed, looked almost like a new work, though the specific choreographic changes were neither obvious nor neumerous. In a nutshell, this abstract homage to ballet's Romantic era has been cleansed, softened and rounded in contour. The atmosphere of moonlit ethereality is all the more convincing as a poetic conceit.

It was, of course, an immeasurable help that Baryshnikov himself danced the sole male role, a kind of prototype of the artist-dreamer pursuing the womanly Ideal. Once again he demonstrated his power of transforming a stage even when standing stock still, as he does at the start of "Les Sylphides" is a pose of rapt, wan musing. But to a remarkable degree, he also managed to imbue his female companions -- Cynthia Harvey, Kristine Elliot, Cheryl Yeager and a notably sensitive ensemble of 16 -- with his own sublety and lyric fluency. Yeager's elfin delicacy was a particular delight.

Baryshnikov's staging of divertissements from the last two acts of "Raymonda" is a far more ambitious project, and a fuller account of its features and merits will have to await future performances. Glazounov's glorious score, as glowingly set forth by conductor Steward Kershaw and the orchestra, and Santo Loquasto's sparely elegant new setting and costumes are considerable enhancements.The most conspicuous stylistic advance is the look and feel of authenticity in the nationally flavored "character" dancing, as in the Mazurka and the big Hungarian number. But the striving toward stylistic integrity was also much apparent in the work of principals Martine Van Hamel, Alexander Godunov, Magali Messac and Kevin McKenzie, as well as the whole ensemble.

Also on the program was a vivacious account of "Rodeo," featuring Jolinda Menendez as the feisty Cowgirl.