The annual folk festival won't be around until fall, and the Mall is awfully quiet for a Fourth of July. So the Smithsonian's Museum of History and Technology and Performing Arts Division have decided to throw their own party. It started yesterday, but continues through tomorrow, and is an attempt to re-create a traditional American Independence Day celebration. It will have six hours (noon to 6 p.m.) of American music in all its modes, from gospel to steel bands, bluegrass to brass, both on stage and wandering through the crowd. Not only will there be street dancing from 5 to 7 p.m., but there will be demonstrations of cakewalls, polkas, mazurkas, Charlestons and the like, and strong encouragement for you to join in. Today, from 1 to 3 p.m., there will be high wheel riders. If you know anything about American festivals, you know that there will be crafts demonstrations and puppets. And anything that moves is likely to be caught up in a race of some sort, for that is the American Way.

The Fourth of July Celebration at the Museum of History and Technology, 14th Street and Constitution Avenue NW, Mall entrance and terraces. Today and tomorrow, noon to 7 p.m. Free. 381-6264.