The fourth production of the Dunster House Opera is also, by far, its most ambitious. In past years, the Opera's choice of repertory has reflected the limitations of its all-student cast; last year's one-act Gianni Schicchi and the operetta Die Fledermaus were light comedies, allowing spirited acting to make up for the inevitable vocal shortcomings. This year, however, the Opera has set its sights considerably higher: the production is Mozart's "Marriage of Figaro," one of the most beloved operas, and it is performed with very few cuts, coming in at almost 3 hours running time.

"Figaro" is not demanding in the same way as a Verdi or Wagner opera; sheer volume and range are less important here than lyric grace and vocal agility. But in some of Mozart's more convoluted ensembles--"Figaro" boasts several scenes in which more than six people are singing simultaneously--that agility can be just as difficult as a louder and showier Verdi aria. Just the elaborate recitatives, which are crucial to advance the plot, require a daunting combination of comic skill and vocal dexterity. What's more, "Figaro" has at least five major singing roles, and a weak voice in any of them would hurt the opera considerably.

Given the scale of these challenges, the Dunster House Opera's production must be counted as a great success. On Saturday night, the audience's enthusiasm only increased as the opera stretched on to midnight. The numerous ovations and spontaneous laughs were proof that people were actually having a good time.

With past student operas, it has been easy to be impressed without being really interested, but in this "Figaro", opera was what it should be: entertaining. This is due in part to the choice of opera, one of the funniest in the literature, and the wise decision to perform it in English; but it is also a testament to the enthusiasm and comic skill of the cast, which knew just how much to ham it up.

Certainly the plot of "The Marriage of Figaro" requires a tongue-in-cheek approach; on paper, it is the kind of convoluted intrigue that gives opera a bad name. Figaro (Brian Saccente), valet to the Count Almaviva (Josh Benaim), is about to marry his sweetheart Susanna (Sarita Cannon), but the Count also has his eye on her. Although the Count has abolished the droit du seigneur, which traditionally allowed the lord to deflower any bride on her wedding night, he is tempted to revive it in Susanna's case. Though a philanderer, the Count is fanatically suspicious of his innocent wife, the Countess (Kate deLima), and her naive admirer, the page Cherubino (Amy Buckley Brown); in his jealousy, he orders Cherubino off to the army, to the ladies' distress.

As if things weren't complicated enough, Figaro has another enemy to deal with: the old spinster Marcellina (Jennifer Little), who has loaned him money on the condition that he marry her if he can't pay it back. The Count seizes on Marcellina's claim as a way of delaying Figaro's marriage, giving the Count more time to woo Susanna.

Also in the mix are Bartolo (Dave Collins), Marcellina's lawyer, who has a personal grudge against Figaro, and Basilio (Jerry Shuman), the castle's unctuous music master, who acts as messenger between Susanna and the Count.

Clearly, the plot is an elaborate game: the challenge is to maneuver all these characters into the expected happy ending. Exactly how that comes to pass is, as one might expect, incredible; but opera was never famous for its realism. Suffice it to say that mothers are reunited with their long-lost children, people are locked in closets and jump out of windows, and there is plenty of opportunity for cross-dressing. Only the music justifies the brazen silliness of the story, and in this case, the trade is well worth making.

Every character gets a solo aria or two to set out his or her essential nature: Figaro is clever and good-hearted, the Countess is heart-broken, the Count is imperious, Cherubino is perpetually lovesick. Almost without exception, this cast handles the famous arias beautifully Saccente has a strong voice and stage presence, and none of Figaro's comic nuances escape him; he is excellent in the patter of 'Aprite un po, Figaro's attack on female infidelity, and in the touching final duet with Susanna. Benaim, as the Count, has perhaps the most pleasing voice in the cast, combining power and a dark, rich tone. Brown has a pretty voice, well equipped for Cherubino's charming arias, and brilliant comic instincts--her arm-waving and swooning in the cross-dressing scene is hilarious.

The Countess and Susanna have some of the most difficult vocal writing in the opera, and deLima and Cannon are at least equal to the challenge. Cannon's tone is strikingly beautiful--soft and delicate without being precious.

In Saturday's performance, however, she was the only cast member to lack adequate volume, and was usually drowned out in the ensembles. She was shown to best advantage in the recitatives and in her fourth-act aria, 'Deh vieni non tardar,' which allowed her voice's sheer loveliness to dominate the stage.

Kate deLima is one of Harvard opera's old reliables--she has been in the Dunster House Opera for the last two years, in addition to several other musicals and operettas. She was the only cast member who was conceivably able to sing the Countess' heavy and melancholy arias; as a junior, she is already a grande dame. For volume and range, her voice was unmatched. Her only deficiency was a certain shrillness or brittleness of tone, which was especially noticeable in her duet with the sweet-voiced Cannon, 'Canzonetta sull'aria.'

Even the orchestra exceeded the usual standard for student performances. There was, as always, some slackness of tempo and wobbling in the strings and horns; but over the long and difficult haul, the orchestra only improved. Only rarely, as at the end of Act II, did it drown out the singers.

With excellent leads, and a variety of clever and funny supporting players, the Dunster House Opera has produced a "Figaro" not to be missed by anyone who likes opera, Saturday's performance had a long waiting list, so make your reservations now.