The Metropolitan Opera opened its 99th season triumphantly last night with a star-studded "Rosenkavalier" that had the audience on its feet shouting and clapping until well past midnight. It was a striking contrast to last year's opening night when Renata Scotto, singing "Norma," was greeted with a chorus of boos from the audience.

The focus of this year's opening night was the beautifully interpreted Marschallin of soprano Kiri Te Kanawa, who was making her Metropolitan debut in the role, one that she was clearly born to sing. But the evening was above all a triumph of ensemble performance, and Kanawa's brilliant interpretation was matched by equally distinguished work from the other principal members of the cast: Kurt Moll as Baron Ochs, Judith Blegen as Sophie, Derek Hammond-Stroud as her proud father and, above all, Tatiana Troyanos in the multi-faceted role of Octavian.

The biggest name of them all, tenor Luciano Pavarotti, was "indisposed," a notice inserted in the program explained. The tiny role of the Italian singer was well-filled, instead, by young tenor Jeffrey Stamm, who made his Metropolitan debut a year ago. Pavarotti is likely to be better disposed by Oct. 7, when this season's "Rosenkavalier" is telecast live on PBS and the drum beating for his movie, "Yes, Giorgio" is no longer a priority. Meanwhile, his absence from the seven-minute appearance in the opera's first act was artistically unnoticeable, though not unnoticed.

Beyond the individual talents of the singers, this production embodies two values that are almost synonymous with the name of the Metropolitan Opera -- tradition and an adequate budget. It was the 218th performance of "Rosenkavalier" at the Met since 1913, when the Richard Strauss opera was not quite two years old, and by now the company has learned how to handle the little touches that give special satisfaction in this complex and very finely detailed work of art: the peasant loutishness hidden under the shabby livery of Baron Ochs' lackeys, the carefully controlled pandemonium of the levee scene in Act I that leads up to the Marschallin's great monologue on the ravages of time, the comic business of caring for the stricken baron and then setting a trap for him.

One strength of a company like the Met, when things are going well, is the unassuming competence with which secondary roles are filled--the performance of Jean Kraft as Annina in this production, for example.

There were some problems , mostly the usual opening-night difficulties. The orchestra, unquestionably one of the world's greatest opera orchestras, sounded a bit raw at the beginning, and it took quite a while for conductor James Levine to bring it into proper balance with the voices, some of which also took a while to warm up. The problem was most noticeable for Blegen, who does not make her first appearance until Act II, when the other principal singers have all settled into their evening's work. As Sophie, she must launch almost immediately into some of the opera's most demanding music, and last night she took a while to gain complete control. But thereafter, her performance was superb.

But these were small flaws in a brilliant performance. Kiri Te Kanawa took one of the most subtle detailed women's roles in opera and made it totally her own. She has grasped completely the essence of the role, which is stoic resignation in the face of the inevitable -- the self-control that is the essence of true nobility as contrasted with the self-indulgence that brands her cousin the baron's claims to nobility as false. Her singing was virtually flawless, and her restrained acting gave the opera exactly the touch of gravity it needs to raise it above the level of farce.

The farce element was in equally good hands, with Kurt Moll avoiding the excesses that seem to come naturally in the role of Ochs while giving a vivid, well-rounded and vocally rich portrayal of the utterly deplorable character who gets some of the opera's best melodies.

Troyanos had the most varied role of all and the most challenging in terms of versatility if not of depth. She was equally impressive as the hot-blooded young nobleman and as a peasant chambermaid.