The legendary opera star Maria Callas was lauded for her magnetic stage presence and extraordinary vocal range. Born in New York in 1923 to Greek immigrant parents, she moved with her mother and sister to Greece aged 13. In 1939 she attended the Athens Conservatoire where she embarked on a rigorous vocal training in the Italian "bel canto" tradition. After the Second World War she moved to Italy, where she was mentored by the leading conductor Tullio Serafin, and became one of the most celebrated opera stars of the day, making triumphant appearances at La Scala in Milan, Covent Garden in London and the Metropolitan in New York.

Labour MP and former Deputy Prime Minister Harriet Harman is a lifelong fan, who says that despite Callas' tremendous talent and hard work she was unfairly vilified for behaving like a "diva" in the pejorative sense. She says that Callas was one of the first celebrities to get the full "tabloid treatment", and endured prurient press interest in her relationship with the Greek shipping magnate Aristotle Onassis. We hear from Robert Sutherland, a pianist who accompanied Maria Callas during her world tour in 1973-1974, about their friendship. Joining Harriet and Matthew in the studio is singer, musician, teacher and researcher Nina Horrocks, also known by her stage name Ziazan. She specialises in the "bel canto" technique that Callas trained in, and has a YouTube channel dedicated to the subject called Phantoms of the Opera (https://www.youtube.com/c/PhantomsoftheOpera).

Archive includes: Maria Callas in conversation with Edward Downes, 1967, Angel Records Maria Callas: Today interview with Barbara Walters, 1974, NBC

Presenter: Matthew Parris Producer: Beth McLeod for BBC Studios Audio