The New York City Opera had its biggest box office success with the least substantial of the three productions it brought down to Wolf Trap last week. This is hardly a tragedy, but it may give the company unfortunate guidance for future visits to Washington.

Performances of "La Traviata" and "Tosca" were lightly attended in midweek, while "The Student Prince" drew enormous crowds on the weekend. The box office success of Sigmund Romberg's moth-eaten imitation of Viennese operetta certainly had no relation to the quality of its music or story. It may have had something to do with name recognition, and certainly it had a lot to do with the fact that "The Student Prince" played on Saturday night.

The show has been rejuvenated in this production with script revisions by Hugh Wheeler, and it does have three or four great tunes, including the serenade, the drinking song and "Deep in My Heart." The City Opera production is bright, energetic, prettily staged and sung at a level of quality beyond what the music deserves.

Even with all this help, however, the creaky old show is barely worth a whole evening in a professional theater -- not because it is suboperatic, but because it lacks sufficient color, vitality and human interest. The City Opera cultivates a broad repertoire, including (in recent years) "Sweeney Todd," "Candide" and "South Pacific." All of these are worth running on a stage that also hosts "Traviata," and so would be "Guys and Dolls," "Man of La Mancha" or "Fiddler on the Roof." But "The Student Prince" today is a museum piece, the kind of show whose death knell was sounded when "Showboat" demonstrated the power inherent in American subject matter and American musical styles.

For the record, the cast was generally good, notably Jon Garrison in the title role, Chester Ludgin as his mentor and Stanley Cornett, Robert Brubaker and Robert Ferrier as students. Susan Marsee was radiant as Kathie and Cynthia Rose, who had not much to sing as the Princess, sang it with remarkable power. The chorus was fine visually and vocally, and conductor Jim Coleman demonstrated skills worthy of a better show.