Sontag was born at
Koblenz, Germany, as Gertrude Walpurgis Sontag, to the actor Franz Sontag and his wife, the actress
Franziska Sontag ( Martloff). Her brother was the actor Karl Sontag. She made her début at the age of 6. In 1823 she sang at
Leipzig in
Carl Maria von Weber's
Der Freischütz and in December of that year created the title role in his
Euryanthe. Her success was immediate. She was invited to be the soprano soloist in the first performances of
Beethoven's
Symphony No. 9 and
Missa Solemnis on 7 May 1824; she was only 18 years old at the time. In 1825 she was engaged by the
Königstädter Theater, Berlin. In 1826, she was engaged at the Paris
Comédie-Italienne, where she debuted in the role of Rosina in
Gioachino Rossini's opera
The Barber of Seville. She was also successful in performance in England and Germany in the following years. When she visited
Weimar,
Goethe wrote a poem dedicated to her,
Neue Siren. Around 1829 she married Count Carlo Rossi in secret, after which she left the stage until her husband's financial situation deteriorated. In 1849, she was encouraged by the impresario
Benjamin Lumley to perform a season at
Covent Garden Theatre. She proved to have fully retained her vocal powers. In 1852, she toured America, and in May 1854, at a literary evening in honor of Mexican president
Antonio López de Santa Anna, she made public for the first time the lyrics that
Francisco González Bocanegra had written to celebrate the nation (with an Italian musical arrangement). A day after singing
Lucia di Lammermoor, she contracted cholera, which would claim her life at age 48. Sontag died in
Mexico City, Mexico, and is buried in Germany at
St. Marienthal Abbey. Her sister Nina Sontag (1811–1879), originally also an opera-singer, had retired there as a nun in 1844. == Singing ==