"Marble crystal velvet don't touch work of art gift from the people of," say the tour guides at the Kennedy Center.

"Uh loddie doddie, uh loddie doddie, we like to party, yeaaaaah," sings the D.C. Police rock band.

America's gleaming showroom of the lively arts opened wide its sliding doors yesterday for the second annual "Inside/Out" day. The eight-hour community arts festival is sponsored by the Friends of the Kennedy Center, currently celebrating its 20th anniversary. More than 80 acts that ordinarily couldn't get near the center without buying tickets invaded the front plaza, Grand Foyer, Concert Hall, Atrium and Theater Lab. And for the thousands of spectators who showed up, it was all free.

Magician Hal Diamond is in a straitjacket, hanging from a fire truck's ladder high in the air. He is struggling to get out. He is attached by safety ropes, which takes some of the fun out of it. He frees himself. He is lowered to earth. He produces an American flag.

Mayor Marion Barry tells the crowd of a recent conversation with New York Mayor Ed Koch. "I told Ed, 'We have taken the title away from New York City. Washington, D.C., is the Cultural Capital of America!' Right?!"

The D.C. Police has got the folks dancing in the driveway. A woman is dancing on stage. She's also signing for the deaf rock fans out there. She's Laura Kolb of Columbus, Ohio, in town for a conference of the American Association of the Deaf and Blind. She may be the world's first go-go translator.

"Hi," says a tiny girl to a comparatively huge person in a fuzzy dog costume. "Hi, hi, hi, Mister Doggie. Hi." Somehow the animal costumes the Friends have selected do not produce the fearful response children usually have to tall creatures covered with hair.

The breezy terrace is the perfect setting for an oompah band. Die Alte Kameraden (The Old Comrades) of Fairfax fill the bill. John and Barbara Davenport of Silver Spring dance a schottische -- a German dance that originated in Scotland. Or a Scottish dance that originated in Germany. Anyway, it's popular in the Midwest.

Buskin and Batteau, a folk duo, look great under the Concert Hall's lights and sound great in their acoustic environment. Brian Maslwe of Laurel is impressed. "Somehow folk and the Kennedy Center don't seem to go together." But today they do, and the result, says Maslwe, is "incredible. They should do it more often."

In Memory of African Culture is a sad name for such happy twists, flails, shouts, rhythms, twangings and yellow and orange costumes. The dance and drum troupe draws loud applause from the more-diverse-than-usual crowd in the Atrium.

Alan Alper of Silver Spring has come "to see if there's a demand for my services in the music industry." He's a massage therapist. He's hitting up Julie Parsons and Ann Finn, the singer-songwriter-keyboardists of Foxxfire. "Call me if you're interested," says Alper. They're still pretty excited about having played the Kennedy Center, but promise they will.