BY SIX A crowd had already gathered. The front runners were leaning across the gate, sipping martinis. They came with picnic baskets, folding chairs and tables, even pillows and favorite dolls for soon-to-be-sleepy children.

While waiting some played dominoes, backgammon, Othello and bridge. Others passed the time sitting on coolers reading Herman Wouk's latest, even Plato's Republic. Most, however, kept their eyes glued on their goal, the perfect place for a Wolf Trap concert picnic.

By 7:15 on the Tchaikovsky Friday, appetites were fully whetted. The tension was mounting. Drinks were gobbled down and glasses tucked away. Chairs and tables were folded and personal belongings gathered up. The gate people were ready. at exactly 7:30 the doors swung open and several thousand people rushed onto the lawn. A sea of blankets covered the grass and hungry hands set out the picnics.

Gate people are a concert breed apart. For whatever reasons they prefer the ground to a seat with a back. They prefer racing to their spots instead of a leisurely stroll. They enjoy the company of other gate people.

For the last 10 years retired navy commander Richard Williamson of Arlington has been a gate man. "I like to avoid the crowds and get a good parking place." By six he and his wife Gervaise were sitting on lawn chairs cheek by jowl with the gate. "We eat, read and listen to all the yak." Rain or shine the Willaimsons are there, usually alone, because it is hard to find friends who want to come as early as they. On this hot, sticky evening they were drinking orange crush instead of their regular, wine. Homemade fried chicken, cole slaw and fresh cherries were on the menu.

Not all gate people remain gate people. Take Lou and Judy Priven of Gaithersburg. They vowed never to do it again.

Arriving at 6:10 to buy lawn seats they quickly learned that despite the record breaking heat wave the concert was sold out. So they had to buy $11 seats just to sit outside on their favorite hill. Lou may have botched up the ticket arrangements but not the menu. He proudly presented an Italian gourmet picnic for four prepared by the Italian Gourmet in Vienna, including a bottle of wine for $19. For dessert Priven held up homemade cannolis which, surprisingly, had not melted.

Behind the gate there were all kinds of picnickers waiting for lawn seats. A congenial group from the Georgetown Medical School library had a cooperative dinner with homemade bread, cold pasta salad, barbecued chicken wings, macaroni salad, curried chicken salad with cheese, wine and brownies and peanut butter for dessert. One member of their group apologized for forgetting the guacamole. "Because I had to work the avocadoes are rotting in my kitchen," he mourned. Had he gone a few picnic blankets over he could have tasted an outstanding chicken liver pate with avocado.

Mostly there was chicken. Mostly it was carry-out, but occasionally there was homemade southern fried. There was lemon chicken, sliced chicken, barbecued chicken, a Vietnamese chicken and green pepper sautee. Then there was Italian meat loaf. But mostly there was chicken.

Every level of cooking was represented. Potato salads, potato chips, cold vegetables with every kind of dip imaginable, from homemade boursin to Green Goddess dressing made low calorie with cottage cheese. There was brie, there was camembert, there was even caviar. An English woman served French quiche with Scotch eggs. An American prepared Italian meat loaf with cold pesto potato salad with green beans. Desserts tended to be primarily fresh fruit with some blueberry squares, blueberry pies and fruit salads thrown in. More than one ill-fated chilled wine bottle slipped through its paper crashing to the ground.

Then there were the Hicks of Coral Gables, Fla., enjoying Wolf Trap for the first time. The Fairfax hotel had packed them a picnic on silver and china that started with cold consome, followed by a luxurious plate of cold poached salmon, pate, cold cuts, sliced cheese and condiments. For dessert they had marble cheesecake.It was all packed in a lovely wicker basket. The price? They'd see when they received the bill.

And then there was the annual picnic celebrated by Al Keliert of Dale City. First to arrive at 4:45, Al wanted to get a good seat for his Tchaikovsky birthday party. "Fifteen feet up from the wall in the center" was his choice. So, with homemade martinis and cheese and crackers Kellert and his wife Cheryl started their cocktail hour at 5 p.m. Their children, Amy, 5 and Albert, 4, came armed with soft drinks, dolls, blankets, pillows and coloring books.

Two and a half hours later when the doors opened Kellert, grabbing his enormous cooler, was the first to charge down the hill and race to his front seat lawn blanket place. For the next hour and through the resonance of Tchaikovsky's Symphony No. 5, the Kellerts, with a flickering candle on their plastic lace tablecloth, dined on Smithfield ham and cheese on sesame seed buns with a red wine. During intermission they drank some champagne and while listening to Rostropovitch's son-in-law Pieter daniel play the Concerto for Violin and Orchestra they sipped a sweet white Mouton Cadet while nibbling on apple impromptu, better known as apple crisp. Their children dropped off to sleep to be awakened by the cannon blasts in the 1812 overture. They may have been the first to arrive at Wolf Trap but were probably the last to leave. "We'll do it exactly the same way next year," Kellert said.

Nearby, two young men, seemingly oblivious to all the moving mouths, were quietly reading the newspaper. The only two non-picnickers, they explained that last week they had done the picnic routine. This week they went to Roy Rogers first. They wanted to save their money to go to the beach.

Here are some of my favorite picnic recipes from the Wolf Trap cookbook. PERSIAN RICE SALAD (6 servings) 1 cup raw, long-grained, white rice 3 tablespoons white vinegar 6 tablespoons olive oil 1 teaspoon salt 1/2 teaspoon pepper 1/2 teaspoon tarragon 1/4 cup red pimiento, chopped 1/4 cup parsley, chopped 1/4 cup onion, finely chopped 1 cup green peas, cooked, drained and cooled (or canned small green peas) Lettuce leaves Black and green olives, pitted

Cook the rice according to package directions until just tender. Be careful not to overcook. Drain. While the rice is hot, toss it in a serving bowl with the dressing made by combining the vinegar, oil, salt, pepper and tarragon. Cool. Add the remaining ingredients. Cover and refrigerate at least 4 hours. The flavor matures and improves over 2-3 days. Serve on crisp lettuce leaves, and garnish with pitted black and green olives.

Add almost any combination of vegetables: cooked green beans, cut up; cooked zucchini, cubed; cooked broccoli flowers; mushrooms, raw, canned or sauteed; fresh bean sprouts; lightly cooked carrots, cubed; celery, thinly sliced; tomatoes, peeled and cut in small wedges.

To the dressing, you may add 1 to 2 teaspoons Dijon mustard or 1 teaspoon curry powder before mixing with the hot rice.

This can be expanded into a main dish with the addition of 1 to 1 1/2 cups cooked seafood, chicken or ham. KISMET CHICKEN (4 to 6 servings) 3 cups chicken, cooked, cooled and cubed 1 pound seedless white grapes, cut in half 1 can (6 1/2 ounces) water chestnuts, drained and sliced 1 cup slivered almonds, toasted 1 cup celery, diagonally sliced 1 tablespoon soy sauce (or more, to taste) 2 teaspoons hot curry powder 1 cup mayonnaise Lettuce leaves

In a serving bowl, combine the chicken, grapes, water chestnuts, almonds and celery. In a small bowl, make a dressing by combining the soy sauce, curry powder and mayonnaise. Taste and adjust seasonings. Toss the dressing with the chicken mixture. Chill. Serve on crisp lettuce leaves.

(Variation) 1 can (11 ounces) mandarin oranges, drained, may be substituted for the grapes, or they may be used together, halving the quantity of each. ITALIAN MEAT LOAF (16 to 20 servings) 1 cup soft bread crumbs (perferably French or Italian bread) 1/2 cup milk 1 package (10 ounces) frozen chopped spinach, thawed 1 pound veal, finely ground 1 pound lean beef, ground 1/2 pound sweet Italian sausage, removed from casing and chopped or crumbled 1/2 cup onion, finely minced 2 eggs, well beaten 1 tablespoon salt 1/2 teaspoon dried basil 1/2 teaspoon dried thyme 1/2 teaspoon ground nutmeg 1/2 cup parmesan cheese (fresh, if possible), grated or shredded 1/2 cup pine-nuts (pignola) or shelled green pistachio nuts 1 cup peas, fresh or frozen (thawed)

Preheat oven to 350 degrees. Soak the bread crumbs in milk for 10 minutes.

Drain the thawed spinach well and squeeze out any excess moisture. Squeeze the milk from the crumbs. In a bowl, combine the bread crumbs, spinach and meat with the onion, eggs, salt, herbs and cheese. Mix lightly with hands or a large wooden spoon until ingredients are just blended. Fold in the nuts and peas. Gently pat the meat mixture into 2 long, thin loaves (about 10 inches long). (Do not pack too tightly, as this tends to make a tough loaf). Score the top lightly.

Place in a large baking pan and bake at 350 degrees for 1 1/4 hours, basting frequently with pan juices. If possible, turn the meat over. Bake an additional 1/4 hour (1 1/2 hours in all). Allow to cool in pan, brushing occasionally with pan juices. Place each loaf on a piece of foil large enough to wrap. Cut each loaf into 12 to 14 slices (be careful not to cut the foil). Wrap and refrigerate until time to pack. (One loaf can be frozen for later use). BROCCOLI-FLOWER BOUQUET SALAD (8 servings) 1 head cauliflower 1 bunch broccoli 1 to 2 cloves garlic 1 lemon 3 tablespoons salt 1 bay leaf 1 pint cherry tomatoes, washed

Cut the stems from cauliflower and broccoli and break the tops into similar-sized flowerets. Cut the rind from the lemon (save the fruit for juice), and add along with the garlic, salt and bay leaf to a large pot of boiling water. Boil for about 5 minutes to season the water. Add the vegeatble flowerets, preferably in a vegetable rack to make draining easier. Return to a boil and cook uncovered for about 5 minutes, until broccoli is bright green and vegatables are just tender and still slightly crisp. Drain immediately and cool quickly in cold water. Shake dry.

In a large bowl (a covered refrigerator storage dish is good for picnic packing) arrange the broccoli in a ring around the outside, then a ring of cauliflowerets, and finally a center of cherry tomatoes. Serve with Lemon Mayonnaise (recipe follows). LEMON MAYONNAISE 1 cup mayonnaise 1/2 teaspoon dry mustard Juice of 1 lemon

Mix well and chill several hours to blend flavors. DILL-COTTAGE CHEESE BREAD (Makes one large loaf) 1 package active dry yeast 1/4 cup water 1 teaspoon sugar 1 cup creamed cottage cheese, heated to lukewarm 2 tablespoons sugar 1 tablespoon onion, minced 2 tablespoons butter, softened 2 teaspoons dill seed 1 teaspoon salt 1/4 teaspoon baking soda 1 egg 2 1/4 to 2 3/4 cups all-purpose flour Soft butter Coarse salt

In a small bowl, soften the yeast in the water and mix with the sugar. In a mixing bowl, combine the yeast mixture, cottage cheese, sugar, onion, butter, dill seed, salt, soda and egg. Mix well. Gradually add the flour to form a stiff dough, beating well after each addition. (You may have to add the last 1/2 cup of flour with your hands). Cover and let rise in a warm place until double in bulk. Stir down with a spoon and place in a well-greased and floured 8-inch round casserole or pie pan. Let rise again until double in bulk (about 30 minutes).

Preheat oven to 350 degrees and bake for 40 to 45 minutes until golden brown. While warm, brush with soft butter and sprinkle with coarse salt. BLUEBERRY PIE 1 cup fresh blueberries 3/4 cup sugar 1/2 cup water 2 tablespoons cornstarch 1/8 cup water 1 tablespoon butter 1 tablespoon Cointreau, Curacao or Triple Sec 1/4 cup sliced almonds, toasted 3 cups fresh blueberries 9-inch pie shell, or tart shells, pre-cooked 1 cup heavy cream, whipped and lightly sweetened 1/4 teaspoon almond extract or Cointreau

In a saucepan, mix together 1 cup blueberries, sugar and water. Bring to a boil. Combine the cornstarch with 1/8 cup water and blend into the sauce in the pan. Cook until thickened. Add the butter to the mixture, remove from the heat and cool. Mix in the orange liqueur, almonds and the uncooked blueberries. Pour into a pre-cooked pie shell or tart shells. Chill.Before serving, top with sweetened whipped cream to which the almond extract or Cointreau has been added.