At Fort Dupont, on summer weekend evenings, you will find music and a lot people. It is good to see this city's culture flourishing, not in any multi-million dollar auditorium, but right in the middle of the woods. It is there -- alive and thriving and, also, free. Every Saturday and Sunday at 8:30 p.m., a crowd of about 20,000 to 25,000 people on the average gathers under Washington's orange-blue summer sky for the concerts.

The National Park Service sponsors the local and big-name performers of disco music, modern dance, children's theater, traditional and progressive jazz. The calendar of events stems from the idea of a community-arts program that Al Dale, the director of the Fort Dupont Summer Theater Program, has helped to develop since 1974. The point was to provide entertainment for low-income city residents who could not afford tickets for, say, the Kennedy Center or Capital Centre. It was to be entertainment for whole families, right in their own neighborhoods, requiring no outlay for baby sitters. Now a family can relax among a sea of blankets with a picnic dinner, for a little night music.

The variety of entertainment available at Fort Dupont represents only one of many free summer programs in Washington-area parks. These include lunchtime music, mime, dance, theater and magic at downtown parks like Dupont Circle, and McPherson and Farragut Squares. In a time of gas shortages, that kind of neighborhood entertainment is especially valuable. It also provides an introduction to the arts in a community setting for people who otherwise might never see a professional dance troupe perform or thrill as a seemingly boneless mime twists the imagination with delight. Fort Dupont, incidentally, is a 300-plus acre park that additionally offers a day camp for kids, an animal program with a naturalist, tennis courts, several baseball diamonds, an ice-skating rink and two soccer fields.

Especially for helping to improve the quality of wilting life here during the summer, Washington owes both Mr. Dale and the National Park Service special sweltering thanks.