Ella Fitzgerald well remembers traveling through the South before there was a civil rights bill or a Martin Luther King Jr. to inspire the nation.

Relaxing backstage at the Kennedy Center last night before her concert benefiting the King Center for Nonviolent Social Change in Atlanta, Fitzgerald spoke of having to eat in the kitchens of hotels and traveling by bus with Dizzy Gillespie, ever mindful of segregation.

"I experienced it," she said before her thoughts returned to King. "I met him a couple of times . . . a warm, intelligent man. He was not a violent man. He made sense, teaching us how to act. That's why we're so honored tonight . . . The proudest moment is to know that we're finally celebrating his birthday."

Besides honoring King's memory, the concert marked the first area performance by Fitzgerald since she was hospitalized last year with a lung problem. With her doctor's blessing she began touring again after a month-long recuperation, and though she's thinner now, she still sounds marvelous.

Fitzgerald opened the Concert Hall concert, accompanied by a fine trio led by her longtime accompanist, pianist Paul Smith. As always, pop standards were the order of the evening, but there was an unmistakable air of spontaneity, too, especially when the singer engaged bassist Keter Betts in a high-spirited game of one-upmanship on "In a Mellotone," and when she later teamed up with guitarist Joe Pass for a near-telepathic collection of duets.

Throughout the show, Fitzgerald proved again that she has no rival when it comes to scat singing. Her vocal agility and ingenuity were constantly on display in a variety of contexts: on ballads, burners, even a bossa nova.

But the evening held more refined pleasures as well, moments that readily displayed the singer's lyrical sensitivity and keen control on ballads like "I Was Born to Be Blue."

Other highlights included the effortless swing Fitzgerald and the trio imparted to "Shiny Stockings" and "Teach Me Tonight," the playful arrangement of "After You've Gone," which turned from tender ballad to torrid scat song, and the Fitzgerald-Pass salute to Duke Ellington.

Before the duets, Pass performed a number of exquisitely arranged standards, and it soon became clear why solo guitar recitals are a rarity in jazz. After all, few guitarists possess the combination of technique and imagination that allowed Pass to brighten even a threadbare standard like "Summertime."

The concert was presented by Blues Alley Music Society Inc. -- a nonprofit organization established by the Georgetown Jazz Club to grant scholarships to deserving students -- in cooperation with the Kennedy Center's Office of Cultural Diversity Affairs. According to Blues Alley Vice President Bob Israel, a portion of the evening's proceeds will aid the advancement of the jazz program at the King Center in Atlanta.