IN PETER SHAFFER'S play "Amadeus," it is the premiere of "The Marriage of Figaro" that finally forces Mozart's jealous, devious rival Antonio Salieri to face the truth: Mozart's genius is so awesome that any hope of Salieri's to match it is dashed. From the stage, the deeply shaken Salieri addresses posterity:

"What shall I say to you who will one day hear this last act for yourselves? You will -- because whatever else shall pass away, this must remain."

Exactly 198 years later, Salieri's truth seems no less certain, especially in a production that probes the serious side of the glorious comedy as deeply as the new version by the Washington Opera.

This "Figaro," at the Kennedy Center, is the second of three Mozart productions that director/designer Jean-Pierre Ponnelle and conductor Daniel Barenboim are doing jointly for the Orchestre de Paris and the Washington Opera.

Conceptually, this version's resolute tone -- and the emphasis on the class-struggle side of the drama -- is firmly set early on in a driving, determined version of Figaro's celebrated "Se voul Ballare, signor Contino, il chitarrino le suonero" ("If you would dance, my noble lord, 'tis I will call the tune."). Count Almaviva's valet has just learned that his lordship has decided to revive the droit du seigneur with Susanna, the Countess's maid and Figaro's wife-to-be.

The tune that this still humorous, but unforgiving Figaro will call is not going to be mere gentlemanly sparring -- especially in the commanding performance of baritone Claudio Desderi. The underlying message throughout much of the production is that with duplicity comes betrayal.

This dramatic emphasis is furthered by the austere, and slightly weathered, settings of the Almaviva palace -- utterly different frm the sunny Ponnelle "Figaro" that the Vienna Opera brought here five years ago. The first act's two-story set, especially, captures the "Upstairs, Downstairs" dimension of this tense act superbly. Below is the basement chamber into which the servant couple is moving; above it is the next level of the palace, with a window through which others in the court appear from to time.

It is through the orchestra that Mozart often expresses the passions beneath "Figaro's" stylish veneer. Barenboim, who is as fine a Mozart conductor as we've got, negotiates the tricky divide between rococo elegance and dramatic tension with great authority.

There is no glaring weakness in the cast. In the performance last Sunday, Benita Valente was especially fine as the Countess, her noble music sung with purity and intensity. Marie McLaughlin skillfully captured Susanna's worldly girlishness, though by the fourth act she was vocally fatigued in "Deh vieni, non tardar," Susanna's most eloquent moment. As the Count, Walton Gronroos cut an imperious figure, a bit more so dramatically than vocally. Susanne Mentzer's Cherubino was full of youthful ardor, so much so in "Non so piu" that the aria was rushed beyond clear articulation.

Of the other performances, Carlos Feller's Doctor Bartolo was especially vivid, and Nadia Pelle was lovely in Barbarina's aria.

"Figaro" is a lengthy and intricate creation (so complex that the English surtitles are less workable than in the company's "Boheme"). In this production, the boldness of the dramatic and musical concepts is sometimes not quite matched in assurance by the vocal and orchestral execution. That aside, the production is as fresh and thoughtful as last season's Ponnelle/Barenboim "Cosi fan tutte." THE MARRIAGE OF FIGARO -- Saturday and November 24 at 8; and November 19 at 7 at the Kennedy Center Opera House.