"I want to congratulate each and every one of you {long pause} for getting tickets," Najeeb Halaby told a capacity crowd, clad in everything from black tie to blue jeans, sitting in the chairs, strolling to the refreshment stands and sprawling on the grass last night at Wolf Trap Farm Park.

"You are the fortunate 7,000," Halaby, the Wolf Trap Foundation's new chairman, told the spectators at the opening night of the performing arts park's 1990 season, and there was an air of self-congratulation in the applause that greeted his statement. There were a few empty (but paid-for) seats down in the front rows of the auditorium, but out on the lawn, where people come with picnic lunches and bottles of wine, every square inch was crowded with blankets, sheets of plastic or reclining bodies. Everyone was in a good mood and applauded for a long time when Halaby mentioned Catherine Filene Shouse, the founder of Wolf Trap, and praised "the genius and generosity of one woman" that allowed the audience "to hear beautiful music as it was written 241 years ago."

The night was nearly perfect for Wolf Trap -- dry, with just enough clouds to make the sky interesting, and cool, perhaps a shade too cool for some patrons. "I will never again put my furs into storage," one well-dressed woman near the front of the auditorium told a friend, shivering slightly.

A glittering guest list of more than 600 heavy contributors and influential friends, ranging from Roger Stevens to Roger Mudd and including WETA President Sharon Percy Rockefeller and Martin Marietta Chairman and CEO Norman Augustine, dined royally with gold-plated cutlery under white tents on a hill adjoining the amphitheater. They sipped a 1989 J. Lohr fume' blanc to accompany their Dover sole roulade appetizer; tasted a Napa Ridge 1985 merlot with their stuffed leg of lamb, haricots verts, and tomatoes and beans; and washed down a raspberry summer pudding with demitasses.

Unable to attend were the honorary chairmen of the event, George and Barbara Bush, who had an important guest coming to town yesterday, but the president sent a message containing some of the least surprising statements of the evening: "The performing arts enjoyed here provide for more than entertainment; they also celebrate and uplift the human spirit. In addition to reminding us of life's beauty and wonder, the performing arts teach, challenge and inspire us."

Some of the most challenging and inspiring performances on last night's program were given by inanimate objects: the polymorphic fountains of the Dancing Waters company that performed a sort of water ballet during Handel's "Water Music," and the fireworks, modeled on original 18th-century designs, that were set off by the pyrotechnics firm Ruggieri/USA a safe distance from the Filene Center.

The model for the evening's celebration was the grand concert and fireworks display given in London in 1749 to celebrate the Treaty of Aix-la-Chapelle, which ended the War of the Austrian Succession. But last night's replica was on a somewhat smaller scale. The Ruggieri firm (a lineal descendant of the one that ran the original celebration) used the original plans, which are in its archives, as a point of departure but expanded on them to make the display something like a history of fireworks through more than two centuries. The beginning was fairly simple, with a restricted range of colors and rockets rising only to modest heights. But by the end, the rockets were soaring high into the sky on intersecting arcs, sending out showers of multicolored sparks, whistling, wiggling like airborne snakes and trailing luminous tails across the sky. A cloud of smoke hung over the meadow, changing colors to echo the explosive displays.

On one point, the fireworks carefully avoided following the original: In 1749 a building caught fire and the celebration ended in chaos. Last night it ended in tumultuous applause.

The Dancing Waters, carefully choreographed to the changing moods, rhythms and tempos of the "Water Music," displayed the remarkable variety that can be achieved by fountains that are tightly controlled with artfully designed lighting. There were low, solid-looking walls of water, long, powerful jets, graceful arcs and feathery little outbursts, shifting from blue to green to red or violet, spurting straight up or slipping gracefully to the sides. It looked, sometimes, like a scene from Disney's "Fantasia."

The musicians were the Grande Band, part of the original-instruments organization established by the Early Music Foundation in New York and directed by Frederick Renz. Their playing was idiomatic and strongly flavored, with a muscular band of winds -- 20 oboes and bassoons equaling the strings in number and reinforced by nine horns and nine trumpets, the old-fashioned natural instruments, valveless and very challenging to play but rich and clean in tone. It was as much a joy to the ears as the fountains and fireworks were to the eyes.

At the reception before the concert, Halaby was thinking about the most newsworthy visitors in town and regretting that he could not get them out to his opening night. "We are trying to get Mrs. Gorbachev to come back for our ball in the fall," he said. "We've had the Queen of Jordan and now we would like to have her." It might be a little more difficult, though. Queen Noor of Jordan is Halaby's daughter.