Washington National Opera is celebrating its 50th anniversary season this year, at the same time as the National Symphony Orchestra marks its 75th. Last night, WNO inaugurated its golden anniversary year by the premiere of a lesser-known opera, I Vespri Siciliani (The Sicilian Vespers), by a great and justly famous composer, Giuseppe Verdi.

As an opera never mounted in the company’s history, it was an odd choice, since it is neither an old-guard favorite nor of particular interest to iconoclasts. This is especially true since WNO chose the less authentic Italian translation, created after the work’s Paris premiere as a French grand opera. (We have to agree with a fellow music blogger, Vilaine Fille, who was puzzled about why the Met used the Italian version last season: “I cannot fathom why a U.S. house would perform a work in something other than its original language or our local lingua franca, English.”)

The WNO audience, perhaps also finally fed up with rising ticket prices, seems to have shied away, and we observed more empty seats last night than we would have expected for a 50th anniversary season premiere. Not even offers of severely reduced-price tickets to Generation O members seem to have been able to fill the house to capacity. We will see how what critics have to say in their reviews this week will impact attendance further. We still think that you people might enjoy yourselves at Vespri, if you can buy a reduced-price Generation O ticket.

Before last night, of all the singers in this cast, we were most excited about hearing soprano Maria Guleghina. Last season, we read reviews from newspapers and opera blogs in New York City about her performance in Nabucco at the Met, and she was usually described as an overwhelming vocal experience. That power was on hand last night, but Guleghina seemed uncomfortable in the role, dropping a line in the opening of the fifth act, for example, before she recovered and appearing to have trouble with her high notes at the end of the fourth. Maybe she was under-rehearsed, or over-rehearsed, but this was not a particularly rewarding performance in what is, admittedly, a very difficult role. Even so, she received a warm ovation for the famous bolero (“Mercè, dilette amiche”) in Act IV, after which an Italian listener near us commented, “Finalmente, della musica!” (Finally, some music!).