There are a few problems with Francesco Cavalli's opera "L'Ormindo," which will have three more performances at the Wolf Trap Barns, but its good points far outweigh its drawbacks, and it's not the sort of thing that happens so often we can afford to let it pass.

In the first performance last night, "L'Ormindo" lacked some of the vitality and polish of the "Barber of Seville" that opened the Wolf Trap Opera Company's season two weeks ago. But it had considerable exotic charm, its blend of comic and serious elements had something for everyone's taste (even a couple of tenor drag scenes), and there were moments of breathtaking beauty.

The opera "L'Ormindo" will most clearly call to mind is Monteverdi's "The Coronation of Poppaea" -- now in its 345th year, which makes it two years older than Cavalli's opus. By 1644, Cavalli was able to get rid of the allegorical apparatus and the Greco-Roman divinities that clutter "Poppaea," and deal entirely with flesh-and-blood characters. But the similarities are more important than the differences.

Both operas use the same kind of stately arioso recitative -- a simple, stripped-down melodic line -- but supple, emotive and endowed with the vitality of music plus the clarity of heightened speech. Both use melody and ensemble singing techniques in ways that recall the Renaissance madrigal tradition, combining grace of movement with vividness and sometimes depth of expression. Both discuss human folly and passion -- love, friendship, treachery, deceit, compassion and even marital boredom -- with a special kind of clear-eyed attitude. It is not really amoral, as it is sometimes described, but it sees clearly beyond the limits of a simple, black-and-white value system and it insists not only on recognizing but also on celebrating all the dimensions and values of lust, pride and resentment in human affairs.

The plot focuses on a love quadrangle that escalates to a pentagon and then settles down to a triangle before reaching its final improbable but happy resolution. Erisbe, wife of the aged King of Morocco, has taken not one but two lovers to console her for her husband's inadequacies. The lovers, Ormindo and Amida, are close friends but do not realize they are also rivals until each shows the other a picture of his secret love in a comically romantic duet. After Amida drops out of the quadrangle, Erisbe and Ormindo decide to run away together. They are captured, the king orders them to be poisoned, then regrets his decision when it is too late. But it is not too late! The executioner -- a gentle man and a friend of Ormindo -- had only given them a sleeping potion. When they awaken, the king (who is by now quite weary) abdicates not only his wife but his throne in favor of Ormindo.

Whatever one may think about the denouement, it does allow the composer to have his cake and eat it, following a double death scene worthy of "Romeo and Juliet" with a mind-boggling happy ending. But the plot does not exist merely to serve as a what-happened-next narrative; its most essential function is to serve as a mechanism for the revelation (and occasionally transformation) of character and -- above all -- as a way of getting the opera from one music-worthy situation, comic or serious, to another.

A significant part of the opera -- for many in the audience, perhaps the most enjoyable part -- is its substitute for the Greek chorus. "L'Ormindo" has no chorus, but secondary characters regularly step slightly out of their roles, or stop the action briefly, to make comments on the situations and attitudes into which the romantic leads have worked themselves. It was in this sort of music that mezzo soprano Margaret Jane Wray, the finest voice on the stage on opening night, made her impression. Similar music was well-handled by Jeanine Thames in the role of a page, Robynne Redmon (a princess disguised as a fortune teller) and tenor William Cotten, performing the role of an old nurse in a style that will call "Poppaea" to mind.

Compared with these supporting roles, the leading singer sometimes seems a bit stiff and awkward, partly because of the music and partly because it takes a while for a nonspecialized singer to slip into baroque style. Paul Austin Kelly (Ormindo) and Ann Panagulias (Erisbe) both began with voices that clearly needed more warming up. Excessive vibrato was a serious problem during their first arias but was later eliminated. Jeff Mattsey (Amida) had the same problem almost until the final curtain. Nicholas Solomon (the king) warmed up his voice nicely by the end but still lacked something in stage presence. Emily Manhart and Timothy Jon Sarris both sang well in supporting roles, but one of the most vivid performers on stage was a supernumerary, Jacobina Martin. She had not a word of dialogue nor a note of music, but her body language was more eloquent than much of what was sung during the opera.

Richard Woitach conducted with his usual care for the effect of the voices -- words as well as tone, fortunately, since this production is sung in English. The sets and costumes were excellent.