The Manhattan School of Music, where Eggerth had given master classes in recent years, confirmed her death.

Dubbed the “Callas of Operetta,” Eggerth was one of the most recognizable and glamorous operetta stars of 1930s, both on stage and film, and her passing was widely covered in German-language news media on Friday. During the inter-war era, composers including Franz Lehar, Fritz Kriesler and Richard Stolz wrote works for her. Eggerth was particularly renowned for her starring role in Lehar’s The Merry Widow, one she reportedly sang more than 2,000 times in five languages.

Eggerth was born on April 17, 1912 in Budapest and made her stage debut at age 11. In 1930, the composer Emmerich Kalman brought the young singer to Vienna where she was quickly discovered by the Austrian film industry. During the filming of "Mein Herz ruft immer nach dir" ("My Heart is Calling You," of 1934) she met the Polish tenor Jan Kiepura, whom she married two years later.

The couple, known as Europe's “Liebespaar” (“The Love Pair”) in Europe, performed together regularly. In 1938, fleeing the Nazis, they moved to the United States, where they soon got work on Broadway and in Hollywood. In 1943, they starred together in an acclaimed Broadway production of The Merry Widow, with Robert Stolz conducting and George Balanchine as choreographer.

A coloratura soprano, Eggerth occasionally appeared on opera stages, most notably starring opposite Kiepura in a Chicago production of La Boheme during the early 1940s.

Eggerth made over 40 films in four different languages (English, German, Italian and French) including two for Metro-Goldwyn-Meyer in Hollywood: Busby Berkeley’s “Me and My Gal” in 1942, starring Judy Garland and Gene Kelly, and “Presenting Lily Mars,” also with Garland and released in 1943.

After World War II, Eggerth and Kiepura returned to France and resumed touring throughout the Europe and the U.S. They made several films and were particularly sought after for performances of The Merry Widow. After Kiepura died prematurely in 1966, Eggerth stopped singing for several years but, at the urging of her mother, she resumed her career in the 1970s.

The last decade brought fresh recognition, with cabaret and concert performances at venues such as the Royal Albert Hall in London, the Metropolitan Museum of Art and the Neue Gallery in New York. She received the Knight’s Cross of the Order of the Merit of the Republic of Hungary, her native country’s highest honor.

Eggerth’s last public appearance was in Oct 2011, when she appeared at a career retrospective event for the Vocal Record Collectors Society in New York.

Eggerth is survived by her sons John and Marjan, and her daughter-in-law Jane Knox Kiepura. At an event in The Greene Space in 2009, Eggerth told WQXR host David Garland that she continues to feel young and alert. “Until the end of my life I want to learn,” she said. “I am still a student; I enjoy it very much.”

Below is an excerpt from that appearance. William Hicks accompanied her at the piano in an old Viennese song. Recorded live on July 8, 2009: