Verdi's "Un Ballo in Maschera," which opened the Washington Opera's Silver Anniversary Season last night at Kennedy Center, has an extraordinary geographical history.

Verdi based the story of "Ballo" on historical fact -- as well as successful operas by Mercadante and Auber -- and conceived it as taking place variously in Sweden, Prussia and medieval Florence. He finally ended up with colonial Boston for the opera's Naples premiere.

Politics guided the decision. The historical basis for the plot was the assassination of King Gustaf III of Sweden on April 27, 1792, during a masked ball in Stockholm. But the subject was dangerous. Italy in the 1850s -- after years of divisionism and Austrian domination -- was on the verge of a revolutionary unification, and the censors of the arts were nervous: vGiuseppe Verdi and his music had become by that time a symbol of the impending independence. Moreover, then as now, political assassinations were a fact of life, and a regicide on stage was simply out of the question.

Verdi was far from naive, and must have known this as he created his musical tale of people who can escape neither passion nor duty. Or at least so argues Francis Rizzo, the Washington Opera dramaturge who is directing the current production at the Opera House.

"What is surprising is that he could have expected to get away with it," Rizzo says. "Where and how to stage the opera today is a difficult decision, and crucial choices have to be made early on." With the recent Metropolitan Opera's "Ballo" not far out of mind, the director adds that "it was understandable in Verdi's day, because to him colonial Boston seemed a very exotic setting.

"But imagine today trying to make an audience accept the elegant musical atmosphere of the score set in a Puritan community, or Ulrica holding a witchcraft open house in a place where women were burned alive at the mere suggestion of sorcery. One thing that recent productions have shown, I think, is that a Boston 'Ballo' simply does not work."

Set and costume designer Zack Brown adds, "We never really considered Boston as a setting; it would go against the music if you listen to it. The problem was exactly where to put it." What Brown and Rizzo have come up with is an elegant Northern European setting that is not specified as Sweden but is certainly not the colonies. "It's very much what Verdi had in mind as he wrote the opera, I think," adds Rizzo, explaining that this approach also makes the most sense out of the music.

The music is the key. A review of the Naples world premiere -- Boston setting and all -- said that "in 'Ballo' the music is everything, exercising such complete domination that in comparison or with it the poetry becomes less than an accessory." Rizzo notes that it is interesting that years later, when censorship was no longer an important factor. Verdi made no attempt to return the opera to its various original settings, perhaps realizing that a strict historical treatment would not be completely satisfactory either, "Zack and I realized that we had other choices, that it was not a matter of Boston or Stockholm. We simply tried to listen well to the music and it told us what to do."

What they have created is a realistic and opulent production, with Zack Brown's colorful costumes, Bolshoisolid columns and marble floors. Brown, who will be responsible for designing all but one of the Washington Opera's presentations this season, is noted for these elaborate stagings. His first operatic venture was the controversial 1977 "Doktor Faustus" at Wolf Trap, and other productions of his seen here include the televised San Francisco Opera "La Gioconda," a Wolf Trap "Gondoliers" and the much-acclaimed "Postcard From Morocco." He seems to be part of a retreat from the symbolic minimalism of the likes of Josef Svoboda and Wieland Wagner. But when asked if he sees his work in this light, Browns jumps up, saying, "Oh, my God, no. I would love to do some minimalist pieces. I just keep being asked to do this kind of thing and I'm afraid I may be getting typecast. But Verdi is the most demanding of composers to design for, and the demands of the music are clear and very solid."

The production is a new turn for the company: It is a home-grown affair that will travel to cities like Houston and Miami. Was the scope of the design compromised in any way by the prospect of sharing with smaller theaters? "Not at all," says Brown, who supervises the placement of the sets on stage to the last inch. "Martin Feinstein just kept saying 'Bigger, bigger.' And we made it that way."

Feinstein, the proud new head of the Washington Opera, said before the opening that "we wanted to have something really special for the beginning of the new administration and of our 25th year. I think we made it."