The pattern of the past has been that the New York City Ballet came to the Kennedy Center for its annual engagement in February or March, during what is known in subscription-series parlance as the "spring" season. Last night, however, the company inaugurated a new custom, becoming the first visiting troupe of the autumn and thus "officially" launching the ballet year hereabouts.

But the NYCB carries its own spring with it -- or rather, makes one wherever it shows up, warming and brightening the horizon, and stirring thoughts of perennial rejuvenation. So it was last night, with a program containing a new, disturbingly original Jerome Robbins ballet and a pair of masterworks by George Balanchine.

The new Robbins was created for Mikhail Baryshnikov and Patricia McBride, who are at their subtlest and impassioned best in it, plus an ensemble of six couples. It was originally entitled "Opus 19," after Prokofiev's numeration of his Violin Concerto No. 1 in D Major, the score Robbins chose.

When the choreographer discovered that there exists another ballet by someone else in the same score and hearing the same title, he changed the name of the work to "The Dreamer." The work is "abstract," in the sense of being plotless, but the new designation does tell us something about its character and emotional tonality.

In the last large-scale work Robbins created with a major role for Baryshnikov -- "The Four Seasons," to operatic music by Verdi -- the latter's part was brilliant, showy, highly virtuosic in an obvious way. This time, Baryshnikov is the central character of the whole ballet, but the role is poetic in conception and content. It's extremely demanding in a technical way -- for the full 25 minutes Baryshnikov is scarcely off stage -- but anything but ostentatious.

"The Dreamer" is also unlike any other Robbins ballet one can readily recall, with the possible exception of some aspects (particularly the other-worldliness) of the "Dybbuk Variations" of 1974. The beautifully crafted, bitter-sweet ruminations of the Prokofiev Concerto have been translated into an extended dance reverie for which Robbins has devised a movement idiom of exceptional freedom and fantasy. The base is still classical, clearly enough, but the plastic qualities of the moving and still figures of the ballet, especially in the arms, hands and upper torso, have been exploited to the full.

Baryshnikov appears to represent the romantic poet-seeker, in quest of an ever-retreating ideal of womanhood, as embodied in the many-sided role given to McBride. At the opening, in silence and a darkly lit stage, we see Baryshnikov staring outward, motionless, a quartet of kneeling males in the background. As the music moves from dulcet crooning to an increasing edginess, Baryshnikov shudders, prowls and stretches in growing agitation.

After a sudden stop, Baryshnikov sits and watches as McBride makes her entrance and executes a sharp, darting solo which ends in his arms. Thereafter the ballet becomes a series of pursuits, in none of which does the Dreamer ever entirely capture or confront the Dream. At one point in the middle, scherzo movement, the two meet and touch, only to be flung back from one another as if by electric shock. In the coda -- which recapitulates, as does the music the ending of the first movement in mutated form -- the ensemble evaporates side to side from a single file leaving Baryshnikov hovering around McBride, his arms encircling her but not holding her, in an not-quite-embrace. It's a testament to the unattainable romantic aspiration, a sort of updated version of "Sleeping Beauty's" Vision Scene.

Baryshnikov and McBride were magnificent as the Dreamer and his ideal -- the one distracted, befogged and intense, the other mercurial, tempting, fugitive.

"The Dreamer," at first glance, is an absorbing, copiously inventive ballet; whether its structure and development fully sustain its dance themes isn't clear from a single viewing, but assuredly curiosity is whetted for further exposure.

"The Four Temperaments" and "Chaikovsky Suite No. 3" were the Balanchine works, both of them extraordinary. Of the two, "The Four Temperaments" received the more fully realized performance -- Bart Cook, Kyra Nichols, Sean Lavery, Adam Luders and Karin von Aroldingen were the excellent featured participants.