The New York City Opera opened its season at Lincoln Center tonight in an unusual atmosphere. For most of the evening, the performance was like the music--highly competent and occasionally dazzling.

The opening night had been delayed 2 1/2 months by an orchestra strike, and the audience observed the occasion by booing the orchestra heartily at its first opportunity.

The production--Jules Massenet's "Cendrillon"--is an opera based on "Cinderella," and the patrons saved their loudest applause for the wicked stepmother.

Most unusual of all was the use of English subtitles, synchronized with the singing and projected on a screen above the stage. It was the first time this idea has been tried in a major American opera house, and it may have been the first time in history that everyone in an American opera audience knew what was happening throughout a foreign-langugage performance. The difference from opera without subtitles was clearly evident in audience reactions, particularly the frequent laughter at comic punch lines.

This was the first performance of "Cendrillon" in the City Opera's history, and the production managed to strike the proper delicate balance between fantasy, love interest and comedy poised on the brink of slapstick. The company, under the direction of Beverly Sills, had not originally planned to open its season with Cinderella, but with Puccini's "Turandot," launching a summer-long Puccini festival calculated to attract a large share of its patronage from tourists. That plan was destroyed by the orchestra strike, which stretched through the summer while many of the orchestra's members played elsewhere in summer festivals.

Although it became the opening production by accident, the Cinderella story is an apt symbol of the city's second opera company. Like the heroine with the nasty stepsisters, the City Opera literally and figuratively sits in the shadow of the Metropolitan Opera. But the Metropolitan is not an ugly stepsister, merely big and powerful and glamorous. In its company, this Cinderella is still looking for a fairy godmother or a Prince Charming to ends its problems.

In earlier decades, the City Opera was able to hold its own more easily in competition with the Met because, while the Met had more famous voices, City Opera frequently had more imagination. It cultivated theatrical as well as musical values in its productions. It programmed a lot of good operas that the Metropolitan would not think of touching, and it had a wealth of high-quality talent in young American singers who were ignored by the Met.

Now, under the direction of James Levine, the Metropolitan is fishing in waters that once belonged almost exclusively to the City Opera: broadening its repetoire, making its productions more theatrical, and hiring young Americans. The City Opera's summer festival was planned primarily to give it a season when the Metropolitan would be closed. The delayed opening night leaves it only five days before the Met opens Monday. It still has the attraction of a lower range of ticket prices, some as low as $3.50, and now the use of subtitles, which will be featured in all future foreign-language productions.

The foot-high subtitles are printed on slides and projected on a wide screen about 4 feet high that runs the length of the stage and rests at the top of the proscenium. Translations are flashed on the screen one or two lines at a time, sometimes simplifying the words slightly and not attempting to track all of the verbal repetition found so frequently in opera.

The cast performed effectively under the baton of Mario Bernardi, but special mention must be given to Faith Esham and Maureen Forrester, two singers familiar to Washingtonians, including one who is internationally famous in the role of Cinderella and her wicked stepmother.

Esham was appealing throughout, even with some warming up problems near the beginning, and she carried effectively the most demanding and versatile role in the opera.

Forrester's role was much more specialized, although a whole universe away fom the Mahler repertoire that has made her famous. She waded into her comic assignment full steam ahead and with elbows flying in all directions, tossing her body and voice around like a distaff Falstaff and not hesitating to push her voice toward the baritone range for comic effect. She was utterly marvelous and would have been even if she were not abusing one of the world's great voices.

Baritone William Parker--the only male voice with a major role in this opera--was the noble, sympathetic, long-suffering and rich-voiced father of Cinderella. Delia Wallis sang effectively in the trouser role of Prince Charming, and Erie Mills was a brilliant fairy godmother, particular in the long fantasy scene of Act 2.

Secondary roles were filled with the care always shown in City Opera productions, and the frequent ballet sequences were charming if not always dazzling.

As for the orchestra, the audience that booed it at the beginning applauded it warmly when Maestro Bernardi came out to be in the final act. The applause was earned.