The new episode "The Magic of Callas" revisits superstar soprano Maria Callas's 1964 return to the opera stage in London, reprising one of her signature roles: the fiery heroine of Puccini's "Tosca." Callas hadn't performed in public for more than two years due to a turbulent social life, and fans feared that jet-set lifestyle had damaged her voice. This London performance, seen via filmed excerpts from the opera's second act, cemented her stature as a true legend. Interviewees include baritone Thomas Hampson, soprano Kristine Opolais and singer-songwriter Rufus Wainwright.