[2][1] She was active as a voice teacher in Berlin at the Stern Conservatory, her alma mater, until the rise of Nazi Germany in the 1930s.

Due to her Jewish heritage, she fled to Brussels in 1939 and remained there until 1942 when she arrested during the German occupation of Belgium during World War II.

[4] The Metzger family lived in Frankfurt during Ottile's early childhood, and she attended schools in that city.

[4] Metzger began serious musical training with Ottilie Hey in 1894, and in 1895 she matriculated to the Stern Conservatory in Berlin.

[2] In 1901, 1904, and 1912 she performed in The Ring Cycle at the Bayreuth Festival;[2] appearing to acclaim in the roles of Erda and Waltraute.

[1] In 1902 she made her debut at the Royal Opera House (ROH) in London;[2] appearing that year in productions of Die Meistersinger von Nürnberg, Siegfried, and Tristan und Isolde.

[4] In 1922-1923 Metzger toured the United States as the lead contralto in Leo Blech's German Opera Company.

[4] Thereafter, Metzger only performed periodically in concerts and as a guest artist in operas; mainly devoting her time working as a voice teacher.

[1] She gave her last concerts in 1933 under Bruno Walter in Berlin and Otto Klemperer in Dresden, with the seizure of power by Hitler.

[13] In 1933, the American theatre impresario George Blumental (a former associate of Oscar Hammerstein I, who in 1917 had tried to set up theatres for American troops in Paris), tried to arrange with Georg Hartmann and Arthur Hirsch to bring over conductor Blech and a troupe of 12 Jewish opera singers to present Wagner's Ring in New York.

[2][4] With the German occupation of Belgium during World War II, Brussels was no longer safe for Metzger and her daughter.

The fact that her father was not Jewish and a Protestant spared her from being sent to a death camp, although her half-Jewish heritage did lead her to be fired from her secretarial job in Brussels and her legal documents marked her as a Jew.