For nearly two centuries it has been the bane of operatic stage directors that the dying Mozart turned some of his final efforts to composing "The Magic Flute."

In doing so he created out of the theatrical rags of a notably unstage-worthy, sometimes downright silly, text one of the most eloquent musical assertions of humanistic values.

The problem, since 1791, has been that Mozart's music is incomparably more dramatic than any director can make the stage action that goes along with it. And the Washington Opera's "Flute," which opened last night at the Kennedy Center, not only fails to solve the old problem, but actually compounds it.

The music goes well, if not brilliantly. But the production, rented from Ottawa's National Arts Center, makes the fatal mistake of actually detracting from the flow of Motart's music for the sake of the dramatic action. Repeated scene changes - with the curtain going down and the music coming to a halt every time - often slow into tedium what might have been a quite pleasant version of the opera.

In fairness, the Washington Opera should not be fully blamed for such theatrical misfires as long as financial necessity continues to make it dependent on renting other companies. But the Washington Opera would have "Flute" or find another opera. That other "Flute" should have followed the traditional way of reconciling the imbalance between the words and the music - that is, to let the story interfere with the notes as little as possible.

The opera's basic allegorical subject is the clash between the forces of night and day, or good and evil. But instead of facing it on the scale of Milton's "Paradise Lost," librettist Emanuel Schikaneder wrote a rather thin fairytale, with implicit reference to Hapsburg religious repression. The latter of course, is totally lost on modern audiences. That religious issue, though, was a matter of such passionate concern to Mozart that much of his score is indeed Miltonian. It is in these scenes, the heart of the work, where the Washington Opera production fails most notably.

In the lighter scenes, however, this version takes it easy and lets the music flow freely. The evening opens with a most delightful serpent chasing Tamino. And the designs are charming for the armadilo, turtle, elephant, baboon and other animals that gather when Tamino plays the flute.

And the spectacular first act aria of the raging Queen of the Night is staged quiet grandly - with the queen looming on top of a high pedestal and her black veil reaching up into the darkness and covered with glistening stars.

But to maintain the focus properly on the music, "The Magic Flute" must move along with a minimum of interruption, particularly between scenes. Ideally, the 22 arias, ensembles and so on should move along like the movements of an orchestral work - the intermission excepted, of course.

In the Ottawa production this sense of pacing is lost. The halts are frustrating enough in the first act, but in the 11-scene second act, where much of the most exalted music is sung, the effect is positively deadening robbing the music of its cumulative momentum. The stately final scene seems merely the end, and the score explicitly states "change of scene without curtain" before it.

A more expeditious approach to scene changes would be to use action in front of a scrim while sets are being moved; or, better yet, use the turntable on the Opera House stage. Both are impossible with the Canadian sets.

If, though, the Washington Opera cannot control the production concept, it does control the performers. This is no all-star "Magic Flute," but as Ingmar Bergman's movie version showed, stars are not essential.

juding from the performance at the final dress rehearsal, the stand out in the cast is tenor David Kuebler as Tamino. he phrases with style, his high tenor voice is sonorous, and his diction was by far the best of the evening. Why bother, one wonders, to perform Mozart in English, when the words are so indistinct?

Patricia Wells' Pamina suddenly took fire at the beginning of the final duet, with unexpected tonal force, and elsewhere she was more than competent. Louise Russell's Queen of the night goes well except for some hard notes and a failure to articulate the coloratura turns. Her staccato high notes were impeccably executed and she brought strong force to the characterization.

Less distinctive were Jack Gardner as papageno, an amiable actor but a somewhat casual phraser, and Richard T. Gill, a dry and stiff Sarastro. Of all the roles Sarastro benefits most from a major voice; without it, he does not emerge as the dominant figure the score requires.

Conductor Leopold Hager is a real find. The orchestra was playing Mozart in a mellifluous way rare in this city. The tempi were fluid and the phrasing graceful. Hager must have Mozart in his blood. he is the director of the Salzburg Mozarteum and made his Met debut last year with "The Marriage of Figaro."

It is a shame that a production containing so many satisfying parts is no more successful as a whole. But as long as financial necessities rule out long as financial necessities rule out the Opera's staging its own works there is this extra risk of failure, though sometimes borrowed productions work beautifully, as in last year's "Madame Butterfly."

The company has now reached the black in its graduated climb out of the $200,00 deficit general director George London inherited when he took over two seasons ago. The budget is now $1 million, as against last season's $650,000, and yearly increases in both spending and in the number of productions are planned over the next five seasons.

Had the Washington Opera designed its own sets, this "Magic Flute" would have cost at least $150,000. It will be at least a year or two before the Opera's financial house will be sufficiently in order to launch such initiatives.

"The Magic Flute" will be repeated on Sunday and again the following Saturday. It will run in repertory with Donizetti's "L'Elisir d'Amore." which opens Tuesday and will be repeated Friday and the following Sunday.