Union Station seemed to be destined and waiting for the extraordinary event that graced it last night under the rubric "Union Station Dancing." Every aspect of the terminal -- its architectural grandeur, its monumentality, its vast, vaulted spaces, its trains, the hubbub of pedestrian traffic, the commingling of commerce and transportation, the sense of a crossroads of a capital city's comings and goings -- seemed called into play and vivified through the music and dancing of this unique occurrence.

The event also marked the launching of "Dancing in the Streets/USA," a national program to bring performances to public spaces in five major cities (Miami, Los Angeles, Philadelphia and Chicago are the others) over the next nine months. The Washington kickoff, like the sequels elsewhere, was free, part of the overall concept being to draw audiences as diverse and unspecialized as possible. The sponsoring organizations here were Washington's Dance Place and the New York-based Dancing in the Streets.

The participating artists also drew upon the two cities: from Washington, choreographer Liz Lerman and her Dance Exchange troupe (plus 25 guest performers), musician-composer-singer-storyteller Djimo Kouyate, and the justly famed Eastern High School Choir, directed by Joyce Garrett; from New York, composer Christopher Janney, dancer-choreographer Marta Renzi and her Project Company, and choreographer Stephan Koplowitz (who conscripted an ensemble of 14 Washington dancers for his contribution).

All these artists have worked previously in the realm of "environmental" performance, but "Union Station Dancing" brought them together for the first time in an inspired collaboration, as they mutually explored the performance potential of one of the city's, and the nation's, most remarkable sites.

Dancing in the Streets executive director Elise Bernhardt served as master of ceremonies, and drew public attention to the successive program elements with minimal announcements on the public address system. Even before this, however, passersby, travelers, shoppers, diners and tourists were alerted to the event with the help of Janney's sound installation, which "wired" the station's entrance doors in such a way as to fill the Main Hall with anticipatory music, triggered by bodies passing through the portals.

Lerman's "May I Have Your Attention Please!" set its motley cast of children and adults of every age -- the typical Lerman mix -- to crisscrossing the floor with runs and falls, defining subspaces with ritual or gestic asides, and even, at one point, transporting some tall boxed trees into a stately dance of their own. It was amazing how quickly the dancers' stylized actions and rhythms transformed the workaday atmosphere of the station into something magical, a change quickly sensed by the gathering crowd. One could see the normal, random station life, still visible at the far edges of the hall, being osmotically drawn into the fascination of the performance. Perhaps as many as 1,500 people eventually joined the throng. Beyond this, Lerman's choreography -- based on improvisational material to which the performers contributed -- managed to evoke everything from voyagers racing to departures, to the wondering upward gazes Union Station inspires in all who traverse it, to the humorous spectrum of postures people assume in trying to sleep or get comfortable on trains.

The first of Renzi's two offerings, "Romance in America," was a double duet performed around the narrow rim of the station's circular bar, in the middle of the Main Hall, to Irving Berlin standards. One couple was attired in ballroom formals; the other in western garb. The exchange of partners -- and styles -- made the point that in this country, rube and city-slicker enjoy a raffish trading of styles. Given the characteristic mobility of American society, regional, social and other dividing lines tend inevitably to be crossed and recrossed, resulting in a merry profusion of hybrid dances.

Kouyate held forth next, playing a mellow, susurrating and enchanting ballad on the 21-string kora, a lute-type instrument of his native Senegal. The Union Station acoustics enveloped the plucked string sounds in a sweetly enhancing reverberant halo, through which, nevertheless, the seductive intricacy of Kouyate's rhythms and gently fluctuating harmonies remained plainly audible.

Renzi complemented her first piece with "Indian Miniatures," her gloss on the Kama Sutra, here performed as a separate pair of duets in the two circular fountains flanking the Main Hall. The natural interplay between erotic movement and posture, on the one hand, and flowing water -- through which the dancers lyrically trod and splashed -- gave a new poetic dimension to the dance, seen in past seasons in Washington in the more conventional setting of Dance Place. Somehow the piece also seemed, in this context, a perfect counterpart to "Romance in America," celebrating the universality of love in a place where all cultures naturally intersect.

The most spectacular was saved for last. Koplowitz arrayed his performers high on a ledge over the gateway to the station's eastern wing, framed by tall sculpted figures, roofed by a magnificent glass arch, and punctuated in the middle by a giant clock. In surging movements suggestive of adventure, determination, aspiration and struggle, the dancers took on the aspect of imagination's angels, perched in some heavenly loft and playing out the ideals of American history -- a thought redoubled when the Eastern High School Choir burst into "The Battle Hymn of the Republic," and the dancers suddenly raised one of their members high overhead in solemn dirge. The amazing tableaux of these dancers at that height, in those surroundings, basking in the musical radiance of the choir's rich voicings, is something no one who saw it is ever likely to forget.

All the performances drew hearty rounds of applause, but especially the choir, which was begged for an encore (people chanting in unison, "We want more!") and graciously obliged the crowd. The entire performance will be repeated tonight.