It was in Sunday's paper that I first saw the ad -- "The Opera Company Boston -- Coming to Wolf Trap for Four Nights Only." They would be giving one performance of The Flying Dutchman and Madam Butterfly, and two of Aida.

"That's it," I said to myself, "Opportunity is knocking. Get off the dime and answer. First thing tommorow morning, call Wolf Trap."

Monday morning, the phone call between and the administrative assistant for program and production went as follows:

"Will you be needing supernumeraries for Aida?"

"Yes, we will."

"What do I have to do to be one?"

"You have to be available all day next Wednesday, June 11. . ."

"I can be. . ."

"Maybe part of Thursday. . ."

"That's okay. . ."

"And for the performance Thursday night, of course. . ."

"Naturally. . ."

"Also for the performance Sunday night."

"Great," she said, "Just be here Wednesday morning at 11."

"You can bet on that," I said.

"Oh yes, there's just one more thing. The men have to be beardless -- no facial hair."

Cancel all bets.

Ever since I was a kid at camp and our team used the Triumphal March as its theme song, I've loved the music. After 35 years, I can still sing Camp Birchwood's words to Verdi's score. Ever since I learned that opera companies sometimes use supernumeraries, I've wanted to be one. Ever since 11 years ago, I've had a beard and mustache.

When I called my wife at work and repeated the conversation I had with the woman at Wolf Trap, she said, with great compassion, "What a shame, I'm sorry. That's really rough. Maybe next time."

Then I called my friend -- a bearded buddy who had said he wanted to be a super someday, too.

"Hey," I said, "Aida is going to be at Wolf Trap next week and they're looking for supers."

"That's great," he said.

"The only thing is -- they'll just use beardless men."

"Gee, that's too bad. Anyway, I have to go out of town next week." I couldn't decide if he was lucky or unlucky.

That night my wife told our 18-year-old son, "Your father has a big decision to make. He's thinking of shaving his beard."

"Oh no," our son interrupted, "don't do it! It's part of you, part of your personality, part of your mystique. Don't do it."

"But wait, there's more to it," my wife continued, "If he wants to be a supernumery in Aida, he has to shave it off and you know how much he loves Aida."

"Shave it off!" he quickly responded, "Shave it off and then grow it back."

"We'll see," I said.

After dinner I played highlights from Aida on the stereo. That's glorious!

Next morning I said to my wife, "Why don't you go with me? I'm sure they'll need female supers too." Did I want her there for company, or for courage? At first she resisted. But getting her to say she would come with me for next Wednesday's call was like trying to persuande a dieting choloholic to have a piece of fudge.

We were supposed to be there at 11 a.m. Wednesday, June 11. We got there at 10:45. (I would have been there at 10, but my wife needed a second cup of coffee.) I had a razor in the car -- I wasn't going to do "it" until I knew I'd won the part.

We walked through the stage door and to the dressing-room area with a young woman and her nine-year-old daughter who was trying for a super shot, too. The woman told us that her daughter had been in several other shows. She carried a large canvas bag filled with potato chips, sandwiches, sweaters, puzzles, books, etc. "We'll be here until 11 tonight," she said. "She's got to be kidding," my wife whispered to me. She wasn't -- she was right. Actually it was a little after 11 p.m. when we left Wolf Trap that day.

After filling out cards with our names, addresses and vital statistics, we were sent out to the theater to "wait." "Waiting" became our most hurried-to activity that day.

We all were spread around in the theater and on the grass area considering our lunch options when, about 1, the special projects coordinator told all the kids to go to the dressing rooms for costume fittings. At last -- action! Half an hour later, they all came back. None of the kids had been cut, but I wasn't surprised about that -- there weren't that many of them, about eight, and they were all cute (and beardless).

After the children were fitted with costumes, they called for the ladies. I wished my wife good luck -- next to me, I really did want her to be chosen. When she and the nine others came back about 20 minutes later, I asked her if she'd been picked and fitted with a costume. "Fitted! Ha!" she said, "We weren't fitted, we were aligned -- by height! I'm really not tall enough for my costume, but they gave me a belt to hike it up with," she ended with a smug smile.

Just as I took the first bite of a tuna-fish sandwich, they called for the men. I gobbled my sandwich and got up to go. So did dozens of other men! Where had they come from all of a sudden? Were there too many men? Will I make it? She has -- what if I don't?

In the men's dressing room, we too were "fitted" by height. I was tall and short enough for the blue pajama bottoms, long brown robe and sphinx-like hat they handed me. I passed muster. I was in.

That meant my beard was out. I'd known a week ago that it was doomed. My beard would be my offering to the Muse of the Opera. Getting the costume today made it official. Tomorrow, shortly after dawn, the sacrificial ceremony would be private. Tomorrow night my reward would come.

After the costume assignments, since the theater was not ready for us, we were asked to go to an alternate practice area so that the assistant director/stage supervisor could tell us what our roles would actually be. First she gave us a brief and breezy synopsis of the story of Aida (i.e ., "The Triumphal March takes place after the Egyptians have beaten the invading Ethiopians and have now made the world safe for democracy"). We are dubbed the "Egyptian population" and separated into four or so smaller groups to be part of the Triumphal March scene. We went back to the now-ready theater to learn our entrances and exits and to practice the excitement exhibited by a welcoming throng. We were told and re-told not to line up but to cluster and move naturally. It sounded so simple -- it wasn't. We worked industriously at learning to express "spontaneous" excitement. The children were very good. My wife, and a few others, giggled.

The assistant stage director informed us there would be a camel on stage just before our entrance. Each of us resolved in his own way how he would circumvent any reminders of the camel.

After our practice, we were free to watch the the opera company rehearse or to wander around. Now that we had all passed our first hurdles -- we had been accepted and gone through a practice together, we were able to relax. The walls of strangeness melted between us and a spirit of camaraderie began to develop. Through overheard conversations or our own socializing we were able to get to know our fellow supers as people. o

From the conversation between a man and a woman who had warmly greeted each other earlier, I learned a lot about the many layers of greasepaint on some people. He said to her, "How have you been since the last show we were in? This will be my 60th or 70th time as a super. How many have you been in? No, I've never worked with Sarah, either."

She told him, "Actually, I'm not supposed to be here. My boss sent me home from work yesterday because of this terrible stiff neck I have. He said I shouldn't come back until it was all better . . . I had to ask that woman over there to drive me home tonight. I don't think she lives too far from me in Washington. I don't have a car anymore, so I took a bus and taxi out here this morning, but I don't think the busses run late at night." (For the same reasons, a young man we had become friendly with became our passenger for the "run of the show.")

In answer to my questions, a man about my age replied, "Oh yes, I love opera. What's my favorite? Well, actually I have five or six favorites," he said, naming operas I'd hardly or never heard of. "No, I've never done this before -- never saw opera from this side. I'm a computer analyst and it's hard for me to get away."

In answer to my wife's question, the young father replied, "How did the girls get into this? Well, what happened is yesterday afternoon I took both kids to the doctor for physicals. On the way home, I heard on the radio that Wolf Trap was looking for men to be supers. Anyone between 5'7" and 6'1" who was interested should report to the stage door by 6 that evening. I took the girls with me, and when we got here the woman was very happy to see the kids and asked me to fill out cards on them and to be sure they were here on Wednesday. I had to say, 'Hey, what about me?'"

At 6 they told us to take a dinner break and to be back at 8 for more rehearsing.

"Well, what do you think? Are you having fun?" I asked my wife over hamburgers.

"Fun!" she exclaimed, "today was 90 percent boring!" Grouch, I thought. "And 10 percent thrilling," she continued. We both agreed it was exciting hearing James McCracken, wearing a jeans suit, rehearsing "Celeste Aida." Just as it was marvelous to hear and see Shirley Verritt rehearse in a raincoat with a turned-up collar. We tried to talk about Sarah Caldwell -- what she says and does as she conducts the orchestra and instructs the sound engineer and sharpens the choreography -- but all we could do was babble.

Later my wife told a friend that she believed that the essence of Sarah Caldwell's genius is that she becomes a devoted, loyal and proud mother, daughter, wife and mistress of the music. She would do anything for the music.

At 8 we were back at Wolf Trap for a cast rehearsal of the Triumphal March scene directed personally by Sarah Caldwell. Now that she had all the elements of the scene assembled, she did indeed mix and stir, arrange and rearrange, modify and alter these elements to fit Wolf Trap's unique stage. The soldiers were told how to angle their shields, the standard-bearers were told how to bear their standards and our cluster of the Egyptian population had their entrance side reversed so that everyone assuredly would be in place for the king's entrance. By 11 that night we were told we could go home but to please be back at 5 on Thursday for a final rehearsal before the show went on at 8:30.

When it came time to shave Thursday morning, I chose to shave off the beard first to see how I'd look with just a mustache. Not good, I quickly decided. Needless to say, when I arrived at the office, it was instant polling time -- some ayes, mostly nays, and a surprising number of "wasn't aware of any change's. Everyone wanted to know why I'd done it.

Several people asked me what was the difference between a "supernumerary" and an "extra." Since I didn't know myself, and now had earned the title of "super," I looked up the words in a dictionary. Definition No. 7 of an "extra" is "Motion Pictures: a person hired by the day to play a minor part as a member of a mob or crowd." Definition No. 5 of a "supernumerary" is "Theater: one who is not a member of a regular company and appears on stage without speaking lines or as part of a crowd; walk-on." Extras are hired by the day for a particular shot: Once that scene is photographed, their job is complete. Supers volunteer for a scene and remain for the run of the opera. I also think it's a matter of tradition.

On Thursday at 5 we had another rehearsal. A few were in costume; most still had on casual clothes. Soldiers wearing cut-off shorts marched carrying shields and swords. Maidens in colorful leotards danced. Sopranos in faded jeans sang with vibrant voices. The scene on stage was outlandish. People were behaving like ancient Egyptians yet looked like modern Americans. At 6:30, the Opera Company of Boston treated us to a buffet picnic supper. Then we waited in the dressing area lobby for our cue. The Triumphal March scene is at the end of the first act. We could barely hear the music over the loudspeakers because of the din we were making. By 9 there we were -- ladies of the Boston and Washington opera companies in elaborate costumes, knitting or working crossword puzzles; men in skirted soldier uniforms and aluminum helmets, talking baseball scores or politics. All this made for a humorous counterpoint to the sights and sounds of the earlier rehearsal scene, for now we were behaving normally but looking quite unusual. Then, at last, over the loudspeaker came the announcement, "Everyone please take your place for the Triumphal March."

From the wings, we were able to look out at the audience. Coincidentally, I had found out that one of the men from a branch office would be at the opera that night. He told me he'd be sitting in the second row, on the right side, which was the same side of the theater as I would be. I was easily able to spot Henry, who I knew would soon be searching for me in a crowd of beardless men. My wife whispered to me, "That's what we look like when we go to the theater. Look, that guy is sleeping! I feel like a voyeur."

Finally -- the trumpets blared -- our cue -- we rushed on stage and quickly got swept into the action, having no trouble remembering the few things we were supposed to do. It was easy to look excited -- I was excited! The music that elated me so many times before would, from now on, be heard with this vision before my eyes. Our scene got there curtain calls. I was willing to do an encore.

As we were leaving to go home, we were handed a telegram. Befitting the occasion, it read, "Break a leg. LOVE. The Office Gang." We loved it! We marched to the car humming our song!

The opera was scheduled for a Sunday-night performance as well. However, that Sunday afternoon, there was a terrible storm that effectively cut off all the power in the area. We got to Wolf Trap at 6 as we were supposed to. Wolf Trap was a scene of clam chaos. The emergency generators were turned on and they provided just that -- emergency electricity, not adequate electricity. The staff kept scurrying off for quick conferences and would next be seen with tight, determined smiles on their faces. The men's dressing room fused with the ladies' dressing room and two spotlights provided all the illumination by which most of us dressed and made up. The head makeup man went around requesting eyelashes for Miss Verritt, whose stage lashes had gotten lost in the confusion. And the audience kept pouring in the one remaining entrance -- the other was closed due to a tree's now being horizontal instead of vertical.

Over the loudspeaker at 7:50 came an announcement, "Will all of the cast please go to the backstage area." I knew what was coming. My wife remained innocent. Miss Caldwell got up on a chair and said, "I want to thank you all for your Herculean effort to put on the show. The Egyptian god Phtap must very angry with us for trying to defy him with all our efforts." She went on to say, "But unfortunately the power will not be back for at least four hours and that will create a public hazard; the safety of 6,000 people would be jeopardized." At that point someone yelled, "We love you, Sarah!" The rest of us cheered and clapped. Then the director of Wolf Trap got on the chair. He, too, thanked us. He went on to say, "I'm somewhat surprised, though. Everyone knows how powerful you are, Sarah; tonight is a little disillusioning . . . " We laughed -- with tears in our eyes. It was hard to believe -- it was really over.

Driving home, we both felt like the day after a graduation -- sad but triumphant!

GETTING SUPER In late July, the New York City will perform Verdi's "Attila," Bizet's "Carmen" (two performances), Puccini's "Tosca" and Romberg's "The Student Prince" (three performances. The call for "supers" will go out on Saturday, July 18. The call is 3 to 6 p.m. at the Arlington Hyatt Hotel, 1325 Wilson Boulevard. A total of 80 people are needed: men who are between 5'8" and 6'2", whose suit size is between 36 and 40, and body-builder types between 6'0" and 6'1". Women auditioning should be between 5'3" and 5'8" and wear dress size 7 to 12. For more details call 938-3810, extension 242.