The good news from the Washington Opera's performance Saturday night at the Kennedy Center is that the Eisenhower Theater is okay for opera. Considerably better than okay, in fact; opera as an intimate theatrical experience, one that draws you in and involves you, should fare better in this space than it does at the Metropolitan Opera, at the New York City Opera's State Theater -- or, for that matter, at the Kennedy Center Opera House.

The other news from Saturday night is that Pietro Mascagni's "L'Amico Fritz," the lightweight work chosen to introduce the Eisenhower to the operatic world, proved itself inadequate for such a grand occasion.

The only solid arguments in favor of enormous opera houses (except for the occasional epic presentation such as "Aida" or "Les Troyens") are economic, and they tend to run in vicious circles. You need a lot of space to install a lot of seats to sell a lot of tickets so that you can afford to pay for the kind of high-priced voices that are audible in the far reaches of vast auditoriums.

It is impossible to estimate how many beautiful young voices have been damaged by straining to cope with the acoustics of the vast mausoleums that have been built for opera in the past hundred-odd years. The Eisenhower, with just over 1,000 seats, will not inflict such damage on any voice that deserves to flourish, and that is a blessing for audiences as well as singers. Its acoustics are crystal-clear, not only for musical tone but for diction. The Italian sung Saturday night in the Eisenhower came across with high impact, and the effect should be even more striking with the English of "Ruddigore" tonight or "The Consul" later in the season.

The sightlines in the Eisenhower are first-class; that is to say, it is a competently designed theater. But it also offers a sense of intimacy rooted in its modest scale. Sitting in Row O of the Eisenhower is a significantly better experience, theatrically, than sitting in Row O of the Opera House. One is closer to the stage action; one does not feel like a spectator in a stadium. It is an environment that encourages intense involvement in a work of art.

This does not mean that it is the best hall in Washington for opera. Upstairs in the Kennedy Center, the Terrace Theater still enjoys that distinction -- whether it is being used for opera or not. And the Barns of Wolf Trap have a comparable sense of intimacy and participation, almost as much clarity and a bit more warmth in acoustics, though the sightlines are not so good (except, perhaps, from the front row of the balcony). One advantage of the Eisenhower over the Terrace, however, is that surtitles can be used there. In a show like "Fritz," however, the excellent surtitles unfortunately underscore the essential emptiness of much that is happening on stage.

One problem with performing in a theater like this -- a problem already familiar from the Terrace -- is that you can get away with practically nothing. Theatrical imprecision or lack of definition -- things that would hardly be noticed in the cavernous expanses of a place like the Met -- becomes important in the clarity and intimacy of a place like the Eisenhower. Saturday night's performance was often one of broad gestures, lacking in finely wrought visual detail.

Four singers have significant work to do in "L'Amico Fritz," and in this production all four sang well -- give or take the occasional pinched high note or slight drift off pitch. Their diction was, by and large, worthy of the fine acoustics in the Eisenhower, and the singers worked together gracefully in the opera's numerous and generally good ensemble numbers.

But as actors, the principals, particularly tenor Tonio Di Paolo (Fritz) and Katherine Luna (Suzel) were seldom as convincing or engaging as the opera requires. "Fritz" is a perilously slender construction, and it can work only if the audience is made to care about the aging bachelor Fritz Kobus, who has sworn that he will never marry, and the teen-aged country girl Suzel, who is in love with him.

Luna's voice is sumptuous, but she does not for a moment create the illusion that she is, as Fritz keeps protesting, only "una bambina." After her effective first entry, Luna did not realize the full potentials of a role rich in opportunities to use body language. In Act 3, her problem was compounded by a costume (including a ridiculous bustle) totally inappropriate for a simple country girl. Contrast that performance with this season's "Rome'o et Juliette" at the Opera House, in which soprano Angela Maria Blasi, singing Juliette for the first time, marvelously conveyed the impression that she was still in her teens.

The "Cherry Duet" of Act 2 is justly the opera's best-known segment. Musically, it may be the most beautiful thing Mascagni ever composed; theatrically, it marks the dawning of love -- or the awareness of love -- between the soprano and the tenor. It was beautifully sung on Saturday night, and the staging was properly idyllic, but the singers' acting added nothing at all to the musical dimension.

This was not a problem with John Fiorito, who sang and acted the role of Rabbi David superbly, or with Edward Albert and Christopher King, who were excellent musically and theatrically in supporting roles as Fritz's bachelor friends. But the opera's effect does not particularly depend on the audience's enchantment with these performers, or with Anita Rzonca, who was fine in the tiny role of the housekeeper Caterina.

Mezzo-soprano Cynthia Munzer, in the trouser role of Beppe, the Gypsy violinist, had dramatic problems that were not entirely her fault. The character of Beppe -- presumably written in because Mascagni wanted a mezzo voice in his cast -- just does not fit in a verismo opera. If you pay any attention at all to what is going on, you can't help wondering what this effeminate Gypsy fiddler is doing hanging out with a bunch of Jewish bachelors. Munzer, whose singing was acceptable but not dazzling, tried to act like one of the guys with exaggerated swaggers, pats on the back and a generally macho bearing. And it worked no better than Luna's failure to act like a teen-ager.

The part of Beppe is a key to problems in "L'Amico Fritz" that lie deeper than any given production. Simply stated, the opera is like a meal of hors d'oeuvres. Most of the opera's memorable moments have little or no connection with advancing the plot or developing the characters; they are put in to pass the time prettily. This process begins with Suzel's flower song, "Son pochi fiori," and includes the "Cherry Duet," the song "Bel Cavalier" that precedes it, the duet about Rebecca at the well and nearly everything relating to the character of Beppe.

Why is this character introduced by a long, soulful offstage violin solo? Because it is pretty and it fills time, as does the Gypsy's Act 3 song, "O pallida." The segments that actually move the opera along -- those without which it would not make sense -- can be crowded into little more than a third of its hour-and-a-half length. And the rest is icing on the cake -- often delicious icing, but not really structural.

The other problem is a lack of significant tension in the plot to match the histrionics in the music. The mainspring of the action is Fritz's vow that he will never marry, countered by Rabbi David's proposal of a wager, which the rabbi then wins by making Fritz realize his love for Suzel. If this is not an essentially lighthearted treatment of largely philosophical disagreements and a bet, it can easily become an unpleasant story in which Fritz is bullied and tricked into making a commitment he has chosen not to make. Director Douglas Wager, trying to find or inject some depth into the show, came dangerously close to this interpretation at times. But this problem is inherent in the material, not the fault of an extremely talented director whose "Don Pasquale" was one of last season's highlights.

In the production values that are usually so well handled by the Washington Opera, "Fritz" does generally well. There were a few lighting problems on opening night, but they were clearly one-shot mechanical glitches. Zack Brown's scenery for Acts 1 and 3 is superb and could be recycled if the company ever decides (God forbid) to put on "The Student Prince." But a problem with a painted backdrop (behind the exquisite cherry tree foreground) in Act 2 resulted in a rather disconcertingly wrinkled stone tower.

On its brightly colored surface, "L'Amico Fritz" is a pleasant evening of light, almost meaningless entertainment, a sort of situation comedy that might be titled "Rabbi Knows Best." The music can be enjoyed thoroughly in its own right, and it is very well performed -- as is invariably the case when Cal Stewart Kellogg is the conductor -- though the sound would have profited by more violins in the pit and a larger chorus offstage.

But perhaps the major problem with this "Fritz" is that one expects the opening work of a new opera house to be something more serious and substantial -- or at least more coherent.