It may be that Donizetti's opera "Lucrezia Borgia" works better in a concert performance than it would with sets and costumes. It tells a story of false identities, sinister plots, unbridled (but terribly thwarted) passions with incestuous overtones, and dark, bloody vengeance that made audiences worry about morality in the mid-19th century and about credibility in the mid-20th. Anything that distracts attention from the absurdities of the plot and focuses on the glories of the music is probably a blessing. And that's what "Lucrezia Borgia" got in the Washington Concert Opera's production yesterday at the Lisner Auditorium.

The plot, crammed with wild improbabilities and extreme situations and gestures, exists essentially to move the opera from one Big Moment -- one outburst of intense love, jealousy, anger, blood lust or remorse -- to the next. Once there, the music takes charge and immediately establishes full justification not only for itself but for the creaky plot machinery that supports it. Under the firm, knowing baton of Stephen Crout, those climactic moments came across with tremendous impact.

Even with a larger budget, it is hard to imagine how the opera could have been much better cast. There are three crucial roles, all of which were superbly filled.

Lucrezia, a murderer of legendary skill and energy, but also a mother torn by tender feelings, was sung with a magnificent voice and intense dramatic projection by soprano Nelly Miricioiu. Tenor Robert Swensen brought a bright, ringing tone and considerable acting skill to the role of Gennaro, who is (unknown to all but Lucrezia) her illegitimate son by an incestuous liaison with her half brother. And baritone Timothy Noble projected a grim, unyielding character, vocally and theatrically, as her husband, Alfonso d'Este.

Miricioiu, who will be back later n the season to sing Massenet's "Manon" with the Washington Opera, was given not simply a standing ovation at the end but a stamping, shouting one, which she shared with the company and which continued unabated until the lights were turned up. She earned it with a performance that was given all her skill and energy and left her visibly depleted at the end. The only other woman in the cast, mezzo-soprano Ning Liang in the trouser role of Maffio Orsini, does not have to cover such a wide emotional range, but in Act 2 she has a great duet with the tenor and an aria, "Il segreto per esser felici" ("The secret of being happy"), that is one of the opera's most memorable moments: a drinking song interrupted by a distant chorus singing of death. She brought to this music exactly the right touch of swagger and an impressive, superbly controlled voice.

The care in casting extended down to small supporting roles: tenors Robert Baker and Charles Workman and baritones James Shaffran and Edward Albert as Gennaro's young friends; and bass Jonathan Deutsch in two roles. The chorus and orchestra performed with the precision that Crout always gets from them.

The Washington Concert Opera has established and consistently maintains the highest musical standards while giving local music lovers access to worthy but neglected repertoire. Its next productions will be eagerly awaited.