"Il Trionfo Dell'Onore" at Symphony Space Alessandro Scarlatti, described by the New Grove Dictionary of Opera as "the most important opera composer of his generation in Italy," wrote more than 60 operas, working mostly in the convention-bound medium of opera seria. Who could blame him for wanting to break loose, late in his career, with a lone, irreverent comedy? And loose he broke, in 1718, with "Il Trionfo Dell'Onore" ("The Triumph of Honor"), which was staged by Underworld Productions Opera on Thursday evening in the Leonard Nimoy Thalia at Symphony Space. With an exquisite satirical touch, Scarlatti applied high-flown devices of opera seria to mundane, antiheroic characters, beginning with the womanizing army officer Riccardo, the "dissolute penitent" of the work's subtitle. The action, such as it is, consists of a series of shifting romantic alliances that eventuate in Riccardo's being wounded in a sword fight and recognizing the error of his caddish ways. He reunites with his betrothed, Leonora, whom he had jilted in favor of Doralice (who in turn connects with Leonora's brother, Erminio, and so on), and - in Underworld Productions" translation of the work's title - "Honor Wins Out." Underworld's artistic and music directors, in program notes, make much of the liberties they took in the staging and musical performance, in keeping with the spirit of the Baroque. In particular, Gina Crusco, the stage director, cites the gender-blind auditions, though the casting of Baroque opera was so gender-confused at the time that this touch hardly mattered. In the end, Stephanie McGuire, a mezzo-soprano playing Erminio - originally a soprano castrato, like Riccardo - was the only gender anomaly. Underworld Productions carried the conceit further by clothing each of the eight main characters in identical unisex costumes (by Edgar Cortes), with an added epaulette or apron to distinguish one from another - barely. So a madcap confusion reigned, wholly in keeping with the work's studied silliness, until the characters began to sort themselves out. The musical performance, with Dorian Komanoff Bandy leading a contingent of Sinfonia New York (a string quartet and a single woodwind player) from the harpsichord, was rough and ready. Maria Todaro, a mezzo-soprano, sang most impressively, as Leonora. Eric S. Brenner portrayed Riccardo with a somewhat untamed male soprano, producing remarkable high notes and a gorgeous final descent in his big number, but often veering out of control. Also notable were Catherine Leech as Rosina, a maid; Elise Jablow as Doralice; Ms. McGuire; and Stephen Lavonier, a bluff baritone, as Rodimarte, Riccardo's aide.