THERE'S GOING to be quite a crowd on the stage of the Kennedy Center Concert Hall on Sunday. In an unaccustomed collaboration, the National Symphony Orchestra musicians will have to push their chairs back to make way for dancers up front.

The concert, called "Music That Moves," is the first in a new series of NSO programs aimed at families. The hope is that by incorporating dance, "the audience would walk away with an increased feeling about the music and the movement," says Washington Ballet instructor Lorraine Spiegler, the program's dance director and choreographer of most of the works.

About 65 dancers will take part -- area students as well as professionals, drawn from ballet, jazz, swing and ballroom organizations. Members of the U.S. Rhythmic Gymnastics Troupe will also have a role.

It's such a natural pairing that it makes you wonder why it has taken until the NSO's 10,000th performance (which will be the 1 p.m. show) to make it happen. Many of the musical selections just about beg to be danced to, such as Duke Ellington's "It Don't Mean a Thing If It Ain't Got That Swing," during which the jazz dancers of the Worldgate Dance Company team up with swing dance partners Steve Bailey and Carla Heiney.

"How better to exemplify the title?" Spiegler asks.

Other performers include young dancers from the Duke Ellington School for the Arts, pairing square-dance steps to excerpts from Aaron Copland's score for the Agnes de Mille ballet "Rodeo."

"It's not the famous `Rodeo,' but that doesn't mean we shouldn't approach the music," Spiegler says. "The energy and vitality of the music will be matched by the energy and vitality of the Duke Ellington kids."

Among other works, the program also includes parts of Bizet's "Carmen," with performances by the Spanish Dance Theatre of the Spanish Dance Society; and Debussy's "Danse Profane," made visual by the Washington Ballet.

MUSIC THAT MOVES -- Sunday at 1 and 3 p.m. at the Kennedy Center Concert Hall. Tickets: $10-$20. Call 202/467-4600.