THE METROPOLITAN Opera's belated Kennedy Center debut will finally come tomorrow night, but the company has been visiting Washington at irregular intervals since the spring of 1884. Then it came to the capitol after closing its very first season in New York. Arriving here in February, the company offered its patrons Gounod's "Faust," with Christine Nilsson as Marguerite, "Lucia di Lammermoor," with Sembrich, "Gioconda," with Nilsson and Fursch-Madi, and a "Don Giovanni."

The company returned a decade later, after having sung every opera in six of the intervening seasons in German. Thereafter it appeared in Washington in 1898, 1899 and 1900. After a slight gap it was back again in 1902, 1903 and 1904, then later from 1905 through 1908. A longer hiatus then occurred lasting until 1926 when there was a four-year sequence of appearances. oAfter that, with the intervention of the Great Depression, the Metropolitan did not sing in Washington until the Rudolf Bing era when it came back in 1951, and with only break in 1955, sang two or three operas until 1656. After that the Met disappeared from Washington until its recent appearances at Wolf Trap Farm Park.

In the old days, the Met played in the long gone Poli's Theater. Later it moved to the Fox Theater which was subsequently renamed the Capitol, located at the east end of the National Press Club Building. The limitations of the latter stage became so intolerable that it was commonplace for intermissions to last longer than the music because of the difficulties in moving scenery on and off the stage -- in and out of the adjacent alley. Bing finally said, "Never again!" He was right.

Not until tomorrow night will the Met have enjoyed in this city a great opera theater in which to appear.

From the evidence of the wonders in sound that the Kennedy Center house has projected from the visiting companies of Milan, Paris, Berlin, Vienna and Moscow, it is eminently safe to say that the Metropolitan will sound to better advantage here than it does in its own vastly larger house at Lincoln Center in New York. That auditorium seats over 3,800 people, which is almost 1,700 more than the number of seats in the Kennedy Center when the orchestra pit is fully extended as it always is for large operas.

The difference in size, which affects every aspect of the sound as well as the view of the stage, also has a beneficial effect on the singers, permitting them to sing with a greater sense of ease than they can afford in the huge reaches of the new Met.

The company is coming to Washington directly after closing its New York season. Indeed so immediate is its arrival here following its final performance in New York last night, that "L'Elisir d'Armore" by Donizetti, with which the Washington week opens, was not even heard by New York subscribers until last Thursday night when it had its first and only performance this season!

The repertoire for the coming week includes two great Verdi operas: "Otello," with which the Met opened last fall, and "Un Ballo in Maschera." "It will also bring Washington a signal premiere in Benjamin Britten's "Billy Budd."

In addition there will be one of the Met's finest productions, that of Tchaikovsky's "Eugen Onegin," and its relatively new "Hansel and Gretel." The Metropolitan production of Britten's justly famous all-male opera, based on the Melville story, is one of the most spectacular in the history of the new house. The fighting ship, which is the setting for the entire opera, is magnificently reproduced in superb detail.

In the first conversations with the Metropolitan concerning the possibility of bringing the company into town from the wide open spaces of Wolf Trap, Kennedy Center officials had hoped for a two-weeks visit. However, since every large opera house has to make its plans several seasons ahead, the Met felt it could not offer Washington adequate casts for two weeks without longer time in which to plan.

Even in the single week ahead it is obvious that many of the Met's top singers will not be here. Placido Domingo, whom Renata Scotto calls "the finest tenor in the world," will not be here at all, nor will Scotto, who is sometimes, if incorrectly, called the Met's leading diva. (It does seem at times that she sings more often than any other principal.) Neither will we hear Teresa Zylis-Gara, another of the Met's better vocal adornments these days.

Still another candidate for the role of Otello, Jon Vickers, will also be absent. When you recall that Vickers and James McCracken are the two finest Otellos in the world today, with Domingo clearly growing into the role, it is a shame that none of the three could be here, especially since the opera is the only work being repeated during the week.

McCracken's absence from the Metropolitan's roster is lamented by its music director, James Levine, who agrees that the tenor was shabbily treated by the company in the matter of television appearances. McCracken will be at Wolf Trap in June when he sings Radames in Sarah Caldwell's new production of "Aida," starring Shirley Verrett in the title role.

Luciano Pavarotti, whose publicity these days is reaching super-stellar heights, is signing in "L'Elisir d'Amore" and "Ballo." (You would think, to hear some people lamenting their inability to get seats for either of those two performances, that either of those two operas was greater than "Otello" or that Pavarotti was not surpassed in vocal artistry by Nicolai Gedda, whose singing of Lenski's aria in "Onegin" has stopped the show at every performance in which he has appeared).

Gilda-Cruz-Romo, singing the first Desdemona, was to be sure in that role last opening night. She also sang it at Wolf Trap last summer when Vickers was here. A new Desdemona will sing at the second performance on Friday night. Her name is Atarah Hazzan and there has to be great interest in the prospect of a new Verdi lyric-spinto soprano.

Richard Cassily must be one of the strongest working members of the company: He is not only singing Otello twice in a single week, which is more than enough for most tenors; he is following up his Friday night performance of that part by singing Britten's Captain Vere the very next night, making a week few other tenors would consider.

Why is the Met moving indoors in Washington, forsaking not only the fresh air, hot and cold, of Wolf Trap, but also its more than 4,000 extra seats? For one simple reason: the Met wants to sound and look its absolute best in the nation's capital. And that is an impossibility in an outdoor theater.

So now at last the Metropolitan will have in Washington a lyric theater entirely adequate for its finest productions. The Kennedy Center Opera House is about the same size as the Vienna State Opera, somewhat larger than the homes of the Paris Opera, the Deutsche Oper in Berlin, and La Scala in Milan. Its acoustics have been acclaimed by conductor Karl Boehnm as the finest of any opera house in the world.

Welcome, Met! Break a leg!