Louis Horst, American pianist, composer, musical director, author, and editor, was born in Kansas City, Missouri, on January 12, 1884. His parents, who had immigrated from Germany in 1882, were Conrad Horst, a trumpet player, and Carolina Nickell.
In 1892, the family moved to San Francisco where Horst attended the Adams Cosmopolitan School. He studied violin with John Josephs and John Marquand and piano with Samuel Fleischman.
Beginning in 1902, Horst played piano in dance halls and gambling houses, and was a pit musician at the Columbia Theater. He also played in a concert trio and accompanied violinists and singers.
In 1915, the Denishawn dance company visited San Francisco, and Horst was asked to be accompanist. Within months he became the company's music director, bringing him into contact with Martha Graham, Doris Humphrey, and Charles Weidman. In 1925, Horst resigned from Denishawn and went to Vienna to study with Richard Stöhr in order to increase his compositional skills. He found the experience too rigidly classical and returned to New York where he continued his studies with Max Persin and Wallingford Riegger.
In 1926, Horst was hired by Martha Graham. In time, he functioned as her accompanist, music director, composer, and mentor. Among the works he composed for Graham were Primitive Mysteries (1931), Frontier (1935), and El penitente (1940). During his tenure with Graham, Horst also served as accompanist and musical director for Helen Tamiris (1927-30), Doris Humphrey and Charles Weidman (1927-1932), as well as Agnes de Mille, Ruth Page, Hans Wiener, Michio Ito, Adolph Bolm, Harald Kreutzberg, and others. Horst left the Graham company in 1948.
Throughout his career Horst taught at various institutions, including Sarah Lawrence College (1932-40), Bennington College (1934-45), Teachers College, Columbia University (1938-41), Mills College (1939), Barnard College (1943, 1950-51), Connecticut College (1948-64), and The Juilliard School of Music (1951-64). He also lectured at the New School for Social Research (1931), and at the 92nd Street YM/YWHA (1939-42).
In addition to his activities related to dance, Horst composed scores to five films (titles surmised from the scores): Chile (1943), Atacama Desert (North Chile) (1945), Pacific Island (1949), Rural Women (1950), and Flower Arrangements of Colonial Williamsburg (1953). He also founded the journal Dance Observer in 1934.
Horst defined the forms and structural principles of modern dance. While he recommended than choreography be shaped according to the pre-existent musical architecture, he also composed in such a manner as to have the music follow the needs of the dance, giving the choreography primacy. Robert Sabin wrote that Horst's main principles were "economy of instrumentation, functional relationship to the dance, harmonic appropriateness to the emotional scheme of the work, [and] rhythmic integration."
Louis Horst died in New York City on January 12, 1964.