Call It "The Green Card of Figaro," With Thanks to Mozart ¡Figaro! (90210)," Morningside Opera's blasphemous, brilliant new adaptation of "Le Nozze di Figaro," owes Peter Sellars an even greater debt than it does Mozart and Da Ponte. It was Mr. Sellars who in 1988 set "Figaro" in an apartment in the Trump Tower, the better to bring out the work's continued relevance to an era still struggling with the issues of class and power that bedeviled the 18th century. "Thank God the feudal system remains firmly in place in the United States of America in the "90s," Mr. Sellars said when the production was broadcast on television a few years later. While he used the original Italian text, "¡Figaro! (90210)," which just finished a short run at the New School for Drama in the West Village, goes several steps further. It retains the opera's music - even its aria-and-recitative format - but freely riffs on Da Ponte's libretto in English and Spanish, with slang-filled lyrics that move the action to a Beverly Hills mansion today. In this version, fearlessly written by Vid Guerrerio, Susanna (excuse me, Susana) and Figaro are undocumented Mexican workers employed by the Contis, a real estate magnate and his aging-actress wife. The randy adolescent page Cherubino has become Li'l B-Man, an aspiring rapper pursuing the Contis" daughter. ("Ma'am, I don't mean to sound twisty or pervy," goes one line in his rejiggered "Non so più." "Damn, I just love when a body's all curvy.") The stakes could not be more current, clear or urgent: Firago and Susana face deportation if they rock the boat - if Susana refuses Mr. Conti's advances. That "¡Figaro! (90210)," seen on Saturday evening, remains uproariously funny under the cloud of such serious matters speaks to Mr. Guerrerio's ingenious text and the smooth, clever production, adroitly directed on a nearly bare stage by Melissa Crespo. Joined by a six-member orchestra led with verve and precision by Raphael Fusco, the cast energetically inhabited a world both realistically contemporary and timelessly comic, creating characters simultaneously stereotypical and personal. Two sopranos - Donata Cucinotta as Mrs. Conti and Sophia Benedetti as Susana - were particularly fine, but there was no weak link in an ensemble that also included the baritone Robert Balonek as Mr. Conti, the bass-baritone Carlos Monzón as Figaro and the vocally and physically agile tenor Anthony Chatmon II as Li'l B-Man. If there was something jarring about the final chorus of reconciliation - a celebration of American multiculturalism - coming after the exposure of so much injustice and bad behavior, that was in keeping with the original. Much more than the proto-revolutionary Beaumarchais play on which the opera is based, Mozart and Da Ponte - and, now, "¡Figaro! (90210) " - seek to moderate social critique, to show both good and bad in everyone. All people are horrible, one character in "¡Figaro! (90210) " points out. But not all the time, that's the key.