Bart Cook has the gift of dancing roles as if he had created them. Last week in the New York City Ballet's current Kennedy Center season, Cook gave brilliant performances of inherited roles in "The Four Temperaments" and "Symphony in Three Movements." Last night he gave another one in Jerome Robbins' "The Dreamer," created for, and danced magnificently by, Mikhail Baryshnikov.

Cook portrayed the title role as a poet-dreamed rather than the angry young man of Baryshnikov's characterization. He danced with a sustained legato flow, occasionally punctuated by jagged bursts of energy and the jerky movements of a puppet. Heather Watts was also excellent in the difficult role of the dreamer's Ideal.

Earlier in the evening, Merrill Ashley gave a splendid performance of a role that she created awhile back in the season's first "Ballo della Regina." To see Ashley dance a virtuoso role is to see a dancing manual transformed into a set of flashcards. She makes the choreography completely legible, performing the most difficult combinations with dazzling speed, yet giving the illusion of dancing in slow motion. Robert Weiss, as her cavalier, tore through his solos with a dashing ease, but his performance was marred by frantic partnering.

A program which had begun with a soggy performance of "Agon" ended with a glorious one of "Chaconne." Suzanne Farrell, at the top of her form, danced with a plush precision, stretching every movement, graciously supported by Peter Martins. Together the two capped an evening marked by some of the strongest dancing yet seen during the current City Ballet season.