AFTERNOON AT THE OPERA: Joan Sutherland. “La Stupenda” was one of the most acclaimed sopranos of the 20th century, a singer of such power and range that she was crowned “La Stupenda” by Italian audiences. She had a voice of size and substance, but was trained by her husband Richard Bonynge to sing bel canto roles, showcasing a technique that had incomparable facility for fast runs, elaborate roulades and impeccable trills. With plenty of audio and video clips, we will remember the glory of Joan Sutherland and the luxury of her voice. Facilitated by Marc Courtade, business manager for Tilles Center for the Performing Arts at Long Island University. 3 p.m.