Reprinted from yesterday's late editions.

Wolf Trap Farm Park opened its season Monday night as it has the past four seasons, with the Metropolitan Opera. Under cool skies that cleared after a late afternoon thunderstrom, there were thousands in the big shed and more thousands on the grass.

Some of the listeners on the grass had been smart enough to bring along two blankets, rugs or other handy wrappers to ward off the damp edge that lingered as the sun's last rays faded. There were the usual picnic boxes, thermos jugs and bottles of wine, and the refreshment stands were doing a solid, if not jampacked business.

For the first of its seven performances here, the Metropolitan offered its new production of Verdi's "Rigoletto." While millions saw it on television last fall, this was Washington's first look at the flesh and bones of the new sets and costumes by Tanya Moiseiwitch. What looked like grim functionalism on TV looks more like unimaginative delapidation on the stage.

Moiseiwitch opted for a single, central three-level tower that serves in the three acts as a background for two chambers in the duke's palace, Rigoletto's home, and, finally, Sparafucile's miserable dive alongside the Mincio River. Its effect throughout is that of a dramatic Tower of Babel, pointlessly dominating the stage.

It serves its purpose so poorly that at one point it lets us see the supposedly outraged Monterone pass the Rigoletto he is chasing in fury - we are not supposed to see him but the tower's nooks and crannies let us.

Later on its crumbling wall forces Rigoletto to go around to the door and use his key, but when he really wants to get in a hurry, he simply jumps over the stupid, low barrier. Where the Met formerly had an inspired set by Eugene Berman, it now has a monster that makes impossible some of Verdi's best directions.

But stage direction is another of the weaker points of the new production. Credited to Bruce Donnell, it is generally flaccid, and, in nearly all of the second act, nonexistent in impact. For a positive note, the costumes are appropriately handsome.

The musical side of the evening offered a fair share of strong points and some notable weakness. Cornell MacNeil has been singing Rigoletto for around a quarter of a century. During that time he has maintained his voice in excellent condition, and built a finely drawn characterization.

If there is not always all the juice he would like for "Cortigiani" and the final "Vendettas" that close act two, he still has no trouble in riding the orchestra and ensembles in most places, while he adds a rich sympathy to the scenes with Gilda.

One of the special pleasures of the performance was the presence of Judith Blegen as Gilda. The part is rarely sung with the intense musiciality with which she invests it, especially in some of the most famous phrases of "Caro nome," where she sounds like a fine instrumentalist rather than a flightly soprano. And her feeling for nuance, exquisitely expressed through her lovely vocalism, is a rare quality these days.

The audience almost ruined the end of "Caro nome," with misplaced applause. Fortunately conductor Gianfranco Masini stopped the music dead in mid-phrase until the clappers had quit. He then proceeded to the end of the aria which Blegen illuminated with a superb trill.

In most of the opera, however, Masini provided no more than routine leadership, failing to rouse the fine orchestra to the fire needed in support of "Cortigiani," or the incisive playing that is written into the entire score.

Neil Shicoff sang the Duke of Mantua. His basically good voice is being endangered by consistent forcing that led him straight into pronounced sharping at the end of the first duet with Gilda. The orchestra's entrance openly corrected his lapse. He sings without distinction, driving for the high notes, but giving the phrases little of the elegance that is so vital a part of the role. His acting is that of a cardboard stick.

Justino Diaz was a superb Sparafucile in looks and voice, his motionless pose in his first scene adding a chilling touch. Isola Jones sang well as Maddalena.