“This is hard,” says a voice student, withering under the scrutiny of Maria Callas in Terrence McNally’s Broadway hit Master Class, modeled closely on a series the historic Callas actually conducted at The Juilliard School in the 1970s. “This is hard,” La Divina scoffs. “Where am I?” Over the last half century, the business of bringing the words and music of opera to life hasn’t gotten any easier. The Roman-born conductor and Juilliard graduate Speranza Scappucci shuns jargon and hocus-pocus, and she gives notes nicely. Casually glamorous, with cascading strawberry blonde tresses, she looks younger than her 52 years, projecting none of Callas’s goddessy severity. Yet, as the current crop of aspiring divas and divi from Juilliard’s Vocal Arts program will discover, she lets nothing slide. Which is why operatic superstars and novices who have coached with her swear by her. Fun fact: Scappucci’s session takes place on the very stage where Callas, seven decades ago, lay in wait for the students she called her “victims,” perhaps not entirely in jest. —Matthew Gurewitsch

Attend in person at four P.M. or stream the session live at home (no time-shifting).