Though Ms. Eggerth was known mainly to aficionados at the time of her death, she was a popular international star in the 1930s, when her light silvery soprano and her physical beauty propelled her to success in more than 40 movies, including German-language films written by a young Billy Wilder and MGM movies with Judy Garland. She was the top box-office draw in Brazil and was renowned throughout Europe.
Her stardom only increased with her marriage to one of her costars, the operatic tenor and matinee idol Jan Kiepura, in 1936. The two went on to make movies together, star in ‘‘The Merry Widow’’ on Broadway — in a production choreographed by George Balanchine — and raise two sons.
‘‘On the Continent, Eggerth and Kiepura were household names,’’ University of Illinois film scholar Edwin Jahiel once wrote. ‘‘They were often referred to as Eggerth-Kiepura, the way, in America, one spoke of the Jeanette MacDonald-Nelson Eddy musical couple.’’
Ms. Eggerth was an operetta singer with a light, melodious voice that was colored by a Hungarian accent in all six languages she spoke. The greatest operetta composers of the day, including Franz Lehar, Emmerich Kalman, and Oscar Straus, wrote for her at a time when operetta was a thriving art form.
Singing with a deep connection to the texts that gave significance to even the slenderest of lyrics, Ms. Eggerth elevated a popular art form into the realm of artistry.
‘‘Operetta is really a very erotic thing,’’ she told The New York Times in 2007. ‘‘Today, there is no erotic. On the beach the bikini, two little leaves over the breasts: There it is. That is not sex. Sexiness is something which is not shown right away. The mysterious. You don’t see immediately, but you suspect, and the suspicion makes curiosity, and the curiosity you play around with.’’
Marta Eggerth was born in Budapest. Her father was a banker, and her mother was a singer who encouraged her daughter’s career.
A doctor, called in to look at young Marta’s vocal cords and evaluate her future prospects, predicted that her voice would give out in a couple of years — a prediction that proved to be off by about eight decades.
By the time she was 17, Ms. Eggerth was in Vienna as an understudy for the leading role in Kalman’s ‘‘The Violet of Montmartre.’’ In the best theatrical tradition, she went on for the ailing leading lady, Adele Kern, and became a star.
When Ms. Eggerth was 18, the conductor Clemens Krauss asked her to come work with him in Vienna, but on the condition that she abstain from performing for five years — despite an already-thriving career — and that she concentrate on Mozart instead of operetta.
‘‘Although I venerate Mozart,’’ she said, shortly before her 100th birthday, ‘‘I need . . . more passion when I sing. I am not a Mozart singer.’’
Her stage career took off rapidly. She was cranking out films in Europe, mainly light romantic vehicles with pretty songs. In the days before dubbing, films were shot in several languages, so she might find herself filming a scene first in German, then in English.
She first met Kiepura as his costar in a 1934 film, ‘‘Mein Herz ruft nach Dir’’ (“My Heart Is Calling You”).
Both of their mothers were Jewish, forcing them to flee Europe for the United States in 1938. Ms. Eggerth, who was briefly under contract to Universal Studios in Hollywood in the 1930s, had a short stint on Broadway in the Rodgers and Hart musical ‘‘Higher and Higher’’ in 1940.
MGM brought her back to Hollywood in the early 1940s, but Ms. Eggerth made only two movies, overshadowed by the musical star MGM was grooming at the time: Judy Garland. Ms. Eggerth’s star turn in ‘‘For Me and My Gal’’ (1942), a song called ‘‘The Spell of the Waltz,’’ threatened to upstage Garland and ended up on the cutting-room floor. (It was later included on the original cast album.)
In August 1943, she and her husband opened on Broadway in a revival of Lehar’s ‘‘The Merry Widow,’’ which became their calling card. During the next two decades, they performed the 1905 operetta together some 2,000 times. They toured frequently in Europe, separately and jointly in recitals and stage performances.
When the Cafe Sabarsky in New York invited Ms. Eggerth, at age 92, to do a cabaret evening in 2005, the managers asked whether she would be able to perform for 45 minutes.
She gave them an hour and a half.