Opera Singer. A renown coloratura soprano of the early 20th century, she was best known for her interpretations of the works of Mozart. Born Ilse Kempner ("Ivogun" is a re-working of her mother's maiden name) she was raised mainly in Zurich and studied at the Music Academy of Vienna from her late-teens. A 1913 appearance at the Vienna Hofoper attracted the attention of Bruno Walter and led to his bringing her to the Royal Hofoper of Munich and to her debut as Mimi in Puccini's "La Boheme". In 1916, she was Zerbinetta in Richard Strauss' "Ariadne auf Naxos" at the express invitation of Strauss himself; the role was to become a signature piece, along with another she soon assumed, The Queen of the Night in Mozart's "The Magic Flute". Honored as Royal Bavarian Kammersangerin in 1917, she was soon in demand throughout Europe as well as in London and New York, her roles including Marzelline in Beethoven's "Fidelio", Fiordigili from Mozart's "Cosi fan tutte", Gilda of Verdi's "Rigoletto", Susanna from Mozart's "The Marriage of Figaro", and Ighino in the June 2, 1917 Munich world premiere of Hans Pfitzner's "Palestrina". Maria married tenor Karl Erb in 1921 and was to share the stage with him for a number of productions and recordings. Following Maestro Walter to Berlin in 1925, she was to remain there until failing vision forced her to retire from opera in 1932. After divorcing Erb in 1932 she married accompanist Michael Raucheisen in 1933, then gave up performing recitals in 1934. In the late 1940s, she taught at the Music High School of Vienna, later taking a professorship at the Berlin Hochschule. Essentially blind in her final years, she died of the effects of advanced age. A number of her recordings are available; some critics consider her rendition of the Queen of the Night's aria to be definitive.