The opera diva Maria Callas, a glamorous, commanding, larger-than-life, caustic, and surprisingly drop-dead funny pedagogue, is holding a voice master class at the Juilliard School. Alternately dismayed and impressed by the students who parade before her, she retreats into recollections about the glories of her own life and career. Included in her musings are her younger years as an ugly duckling, the unforgiving press that savaged her early performances, her triumphs at La Scala, and her affair with Aristotle Onassis.