Curt Sachs (German: [zaks]; June 29, 1881 – February 5, 1959) was a German-born but American-domiciled musicologist. He was one of the founders of modern organology (the study of musical instruments).
Born in Berlin, Sachs studied piano, music theory and composition as a youth in that city. However, his doctorate from Berlin University (where he was later professor of musicology) in 1904 was on the history of art, with his thesis on the sculpture of Verrocchio. He began a career as an art historian, but promptly became more and more devoted to music, eventually being appointed director of the Staatliche Instrumentensammlung, a large collection of musical instruments. He reorganised and restored much of the collection, and his career as an organologist began.
In 1913, Sachs saw the publication of his book Real-Lexicon der Musikinstrumente, probably the most comprehensive survey of musical instruments in 200 years. The following year, he and Erich Moritz von Hornbostel published the work for which they are probably now best known in Zeitschrift für Ethnologie, a new system of musical instrument classification. It is today known as the Sachs-Hornbostel system. It has been much revised over the years, and has been the subject of some criticism, but it remains the most widely used system of classification by ethnomusicologists and organologists.
When the Nazis came to power in 1933, Sachs was dismissed from his posts in Germany by the Nazi Party because he was a Jew. As a result, he moved to Paris, and later to the United States, where he settled in New York City. From 1937 to 1953 he taught at New York University, and also worked at the New York Public Library.