The New School / Léirmheasanna

The valet Figaro bustles about, measuring the floor space of the new quarters he will soon occupy with Susanna, while, off to the side, she tries on a bridal hat. These are the beloved characters we know from Mozart’s “Le Nozze di Figaro.” But the unfamiliar music is by Marcos Portugal, born in Lisbon in 1762 and renowned in his time. On Tuesday night, the enterprising On Site Opera gave what it called the North American premiere of Portugal’s “The Marriage of Figaro,” also adapted from Beaumarchais’s incendiary French play. Portugal composed the work in 1799 for a Venice production (13 years after Mozart’s “Figaro” first played Vienna).