Maria Callas, known as 'La Divina,' was the most influential opera singer of the 20th century. She was credited with reviving the 'bel canto' repertoire, particularly the works of Bellini and Donizetti, through her extraordinary dramatic intensity and vocal agility. Callas did not just sing a role; she acted it with a depth of emotion that changed the expectations for opera stars. Her 1951 debut at La Scala in Milan cemented her status as a global superstar. Despite a controversial personal life and a voice that some critics found 'unconventional,' her musicality and phrasing were impeccable. Callas’s legacy is preserved in her recordings of 'Norma' and 'Tosca,' which remain the gold standard for sopranos today. She brought a sense of modern psychological realism to the opera stage that had never been seen before.