This was their night, as it has been for the last nine years: Alexander Schneider and Friends performing at the Kennedy Center, first as the virtuoso ensemble in the Concert Hall, and then as the best dance band in Washington on New Year's Eve.

It was, on Thursday, the Kennedy Center's annual "Night in Old Vienna."

From their stage in the Grand Foyer, Schneider led his string quintet -- made up of musicians who have played in many of the finest quartets of this century -- through waltz after waltz, and before them danced Washington's best dressed, filling the length of the hall -- a sea of heads, moving slowly.

Many had arrived after the night's performance: Schneider and Friends performing a program that featured the waltzes, marches and la ndlers of Brahms, Schubert, Lanner and the encore by Strauss. The musical highlight was Mendelssohn's Piano Trio No. 1 in D Minor.

After the audiences emptied out of the Concert Hall and Eisenhower Theater, dancing room became harder to find, although many found room for expression in the entrances to the theaters. Seating was scarce, and the celebrants had to share benches and stairways with empty bottles and glasses. (Some brought their own bottles of champagne, since the lines at the bars become notoriously long on this eve of eves.) Through it all, the crowd danced and conversed boisterously. After each Strauss and Lanner waltz came to an end, the applause signaled the crowd's approval.

Just before midnight, the waltzes ceased and the quintet performed a pair of Austrian polkas. Then Marta Istomin, artistic director of the Kennedy Center, stepped to the microphone to lead the ritual countdown and proclaim "Happy New Year!" as the quintet struck up "Auld Lang Syne."

"I love to do this," said Schneider afterward. "I wish we always could do this. It is much more human."

And the dancers danced on and the champagne flowed.