All of a sudden, after intermission, there were plenty of empty seats in the previously packed auditorium of the Fine Arts Building at Towson State University. Some prudent members of the audience, anticipating a horrendous noise, had moved out to the standing room, up against the back wall of the auditorium and close to the exits. But most of the empty seats were left by members of the audience who had gone up on stage, carrying with them 58 bassoons, seven contrabassoons and more than 100 oboes.

They were joined by nine horns, nine trumpets and enough percussion instruments to keep six players busy in a rousing performance of Handel's "Royal Fireworks Music" in the composer's original scoring with no strings. "I'm not sure whether it was good or bad," said one of the players walking out afterward, "but it was a once-in-a-lifetime experience."

The performance, which was the conclusion and climax of the 11th annual conference of the International Double Reed Society, was not perfect, but it was glorious filling the hall with a sound that was often if not always splendidly balanced, rich in tone and beautifully homogeneous. These qualities were especially notable in passages that involved dialogue between the high and low voices, or between the full orchestra and a small concertino section of two oboes and one bassoon.

Fears proved groundless for the timid souls standing near the exits. Under the baton of conductor Don Christlieb, who makes his living as a free-lance bassoonist, the volume of sound never got out of control, though once or twice the reeds were drowned out by the brass -- who sounded slightly out of tune when they were playing that loud.

After only one rehearsal, the ensemble playing was sometimes imprecise in early sections of the music, but it could be heard tightening up as the music gained momentum and power and the players got used to the packed conditions together on the stage. It was very good by the end; a little more rehearsal and this ad hoc orchestra, which included some of the world's greatest players performing together with students, could be really spectacular.

Although the performance was more authentic than the modern orchestrations in which this music is usually heard, authenticity was not carried to an extreme. If it had been, the pitch of the instruments would have been somewhat lower, and they might not have been quite as well in tune as they were most of the time. An extremist, trying to recreate the exact conditions of the first performance, would have had to put the orchestra outdoors, and fireworks at the end would have burned down several buildings. There are limits to what we can do in the search for authenticity.

What mattered more on this occasion was the spirit of the performance, and that was magnificent. Nearly 200 players, released momentarily from the supporting roles they usually occupy in symphony orchestras, were recreating some of the splendor of their instruments' great pasts. Their enjoyment was obvious in the way they attacked the music, in the broad grins that covered their faces at the end, and in the footstamping with which they responded to the audience's enthusiastic applause.

The Royal Fireworks came at the end of a week of concerts, usually involving one to six players, in which the oboe and its relatives performed for the most part with grace and delicacy. Last night's show of power brought the conference to a smashing climax.