The Metropolitan Opera began its 100th anniversary season Monday night at Lincoln Center on a suitable note of opulence--vocal, social and economic. Ticket prices ranged up to $300 and the Met grossed $601,000.

Perhaps the most opulent element was the voice of mezzo-soprano Jessye Norman, making her Met debut as Cassandra in Hector Berlioz's epic, long-neglected "Les Troyens," based on Virgil's "Aeneid." But the lavishness of the occasion was reinforced, under the baton of Met artistic director James Levine, with singing of the highest caliber from tenor Placido Domingo and mezzo-soprano Tatiana Troyanos, excellent performances in secondary roles, and a chorus and orchestra that rank with the world's finest.

The stage direction of this production is not above criticism, but on opening night the performance of Berlioz's extraordinarily challenging music came close to that mark.

Socially, there were a few T-shirts in the standing room section, but for the most part it was a celebrity audience in its best formal wear. Seventeen trumpeters blowing fanfares officially opened the festivities. They stood spread out on the red-carpeted, white-marble twin staircases leading up to the grand tier, where dinner tables were set up. Enormous vases of roses, brought in specially for the occasion, decorated the stairs.

An hour earlier, the same steps had been filled with hundreds of formally dressed guests standing to chat and sip cocktails before dining. They included not only the general manager of the Met, Anthony A. Bliss, but the directors of several other opera companies (for example, Ardis Krainik of the Chicago Lyric Opera), substantial contributors and public officials.

At one table, Bliss sat next to Beverly Sills, director of the New York City Opera, a neighbor of the Met in the Lincoln Center, though both insisted that they do not consider themselves competitors. "We're just very old friends," said Sills. "I am so happy he invited me."

"I went to her opening last week," Bliss said. "We always go to one another's openings."

"We hold hands," said Sills, "and my husband gets jealous."

Frank Hodsoll, chairman of the National Endowment for the Arts, said the Met was "one of our top challenge grantees and a great opera company. I am looking forward to 'Les Troyens,' which I have not seen before."

One member of the audience who had seen it before was Schuyler Chapin, former general manager of the Met and now dean of the arts faculty at Columbia University. "From my standpoint," he said, "I am delighted to be back here again--and particularly to see what happened to be my first production as general manager. My feeling this time is that I don't have to worry about it."

Besides opera personalities, the Met opening drew a good representation of the eccentrics who are a significant part of the New York opera scene. One elderly lady had eighth-notes painted on the lenses of her glasses. Asked how she expected to see the show, she said, "I came to listen, not to watch."

Representing the Met's enormous radio audience was John McKinley, board chairman of Texaco, which has been sponsoring the Met's Saturday afternoon radio broadcasts for 43 years and now also subsidizes its television broadcasts on PBS. "If you talk in terms of cost per thousand, it would be very expensive advertising," he said. "But opera fans are very loyal. We know for a fact that they go out of their way to drive to a Texaco station."

Opening this season with "Les Troyens" was a calculated risk that worked. It is a work that only a few companies in or close to the Metropolitan's class would dare think of producing. Besides a first-class orchestra and large chorus, it demands two world-class mezzo-sopranos. On opening night, they were Norman as Cassandra and Troyanos as Dido. The two singers will exchange roles for the next performance, and if either one is unable to sing at a future performance the other may take on both roles for the entire five-hour length of the work.

Either role is a monumental assignment and both were monumentally filled Monday night. Norman, a singer familiar to Washington, where she received much of her training, came to this debut with an international reputation already well-established through recordings, recitals and appearances with the major orchestras of the world--particularly in the music of Mahler. She was well-known before the curtain rose, but in the course of her performance much more was learned about her prodigious abilities.

She dominated the stage, and her gestures had tremendous impact. Vocally, she combined amazing sonority, impressive agility and absolutely secure intonation. She received the longest and loudest ovation of an evening packed with ovations, and was called back twice to take further bows after the lights went up.

Troyanos may be marginally less spectacular in pure vocal resources, but she brings overwhelming dramatic power and conviction to the role of Dido, the queen of Carthage who is loved and abandoned by Aeneas. Among many fine moments in the second half of the opera, she stood out particularly in the love duet with Domingo (which sounded, on Monday night, like the greatest love music ever written) and in her long, intense death scene--essentially a monologue and one that covers a vast universe of conflicting emotions. The two halves of this opera create sharply contrasted musical and dramatic worlds. The first half, showing the fall of Troy, is essentially the world of Greek tragedy; the second, the story of Dido and Aeneas, is romantic melodrama. On opening night, the two singers seemed precisely the right ones for each of their roles. It will be interesting to see if they are equally convincing when they switch roles.

Placido Domingo has recently expressed some doubts about the advisability of his singing the role of Aeneas, partly because it lies higher than his usual roles and might strain his voice. This may be a valid long-term concern, but in his first performance of the role (one of many first encounters with "Les Troyens" in this production) there were no signs of difficulty. He sang with both subtlety and power, encompassing the vocal range of the role with apparent ease and an exquisite sense of style. The role's expressive requirements vary from the purest sweetness in the love duet to an almost Wagnerian heroism in other moments. Domingo seemed ideal in both kinds of music.

In an enormous cast of good voices, several secondary roles stood out: Jocelyne Taillon in the part of Anna; Paul Plishka as Narbal; Douglas Ahlstedt as Iopas and Claudia Catania as Ascanius.

James Levine showed a detailed and subtle mastery of the score. Berlioz demands orchestral colors that had never before been heard in an opera house, and a balancing of solo voices, chorus and orchestra (for example in the Octet and Double Chorus of Part I) that calls for the finest precision. Levine supplied this, and his pace was always dramatically right. His orchestra played with precise ensemble sound and supplied some virtuoso solo and section work--notably a long clarinet solo in Part I and the horn parts in the "Royal Hunt and Storm" interlude.

The chorus was vocally splendid in a dazzling variety of combinations and subgroups, and as an impressive 150-voice whole. Visually, it was more problematic, tending to file on stage and stand in one place (often on risers, like an oratorio chorus) whenever it had music to sing. This is presumably the fault of stage director Fabrizio Melano, who generally gave the whole production a static air. Part of his problem is the nature of the work, which tends to strike statuesque poses--but a more imaginative director could have found ways to enliven the stage picture. The dancing (which is abundant in this work) was splendidly athletic.

The stage settings, salvaged from 10 years ago, hardly justified the cost of storage for such a long period--at least until the final act, which opened with the prows of a fleet of Trojan ships moored on the Carthage waterfront and generated the only visual excitement of the evening when the ships quite briskly and efficiently set sail. The dominant motif of Part I was a set of seven stone slabs set up on pillars--a sort of Stonehenge on stilts. Using the remarkable turntable technology of the Met's stage, these blocks were moved about in a bewildering variety of configurations in mid-action--including, at one point, what seemed to be part of the semi-abstract Trojan Horse. This production may go into the annals of opera as the only one in which the scenery moved around more than the chorus.