As the late afternoon lights turned the White House walls to a soft peach color, President Ronald Reagan gazed out across the crowd of 900 invited guests under the South Lawn tent. Seated in the front row with Nancy Reagan and flanked by Vice President Bush and his wife, Barbara, Charley Pride and Roger Stevens (among others), the president enjoyed an hour-long preview of last night's Kennedy Center tribute to vibraphonist and band leader Lionel Hampton. "Aren't we glad we grew up in the era of the big bands?" Reagan asked. The loud affirmation seemed to speak as much to the demographics of his administration as to the greatness of the jazz giants on stage. Reagan also drew some chortles when he pointed out that Hampton had played for five previous presidents. "Nancy and I were happy to come in under the wire as No. 6."

Hampton, a lifelong Republican who has stumped for many of the congressmen in attendance, recalled his last visit to a Democratic White House. "At that one they had a barbecue. At this one we have caviar." This drew a big laugh from the well-heeled audience, as did singer Pearl Bailey's awkward moment on stage as she wrestled with a microphone. "I don't know which mike is working," she puffed, "but it don't bother me. I was in show business before they had electricity."

Bailey, as usual, stole the spotlight during her stint, tossing a belated birthday greeting to Nancy Reagan (whose birthday was July 6), splitting a line from Willard Robison's "Old Folks" with "he's so . . . (excuse me) . . . democratic," and strutting her sassy self along that first row of honored guests as if she were working a nightclub, not a White House. As she left the stage, Hampton conceded: "Pearl, you're a hot dog."

Hampton took his ever-changing all-stars (including Clark Terry, Art Blakey, Dave Brubeck and Freddie Hubbard) through several selections, including an elegant "Misty" and appropriately swinging "Jumping at the Woodside." "They could play till five o'clock tomorrow morning," Hampton exulted. "And they would, too. Ain't no bigger show than playing for the president."

In turn, the president lauded Hampton's "courage and decency," calling him "a truly great American" whose "raw talent and hard work have made him one of the most respected musicians in America." Testifying to Hampton's legendary time-keeping abilities, he added, "I don't think you've missed a beat in all these years." Except, perhaps, a little heartbeat at being honored in such stellar fashion.