Rosalie was the daughter of Moses and Jennie Marx Joseph. She attended Smith College in Northampton, Massachusetts for three years. She met attorney Edgar Leventritt at a party for her hosted by Irene Guggenheim and he asked her to marry him the next day. Before her father agreed to the match, Leventritt was required to leave from his practice to live with the Josephs in Birmingham for a month to become acquainted. He and Rosalie were married on April 3, 1913.
Leventritt had some renown as an amateur pianist, and was a patron of chamber music. The couple had two children, Marion and Rosalie (Mrs T. Roland Berner).
After her husband's death in 1939 she established the Leventritt Competition in his memory, awarding young musicians with a $10,000 prize, plus an opportunity to perform with major orchestras and to record for RCA records. Van Cliburn was a Leventritt winner in 1954 before becoming the namesake of a similar competition in Fort Worth, Texas. The 1964 award went to violinist Itzhak Perlman.
In 1951 Leventritt established the "Young Audiences" program to bring professional musicians to public schools. She was also a supporter of the Casals Festival in San Juan, Puerto Rico; and the Marlboro Music School and Festival in Marlboro, Vermont. The City of New York presented her with a "scroll for distinguished and exceptional service" at a chamber recital held in her honor at the home of Mayor John Lindsay.
Leventritt resided in Cold Spring, New York and kept an apartment on Park Avenue in Manhattan. The 40-foot by 25-foot music room at her apartment, furnished with a pair of Steinway grand pianos, was a gathering place for musicians and music teachers, and was where young Isaac Stern studied chamber performance.
She died at Lenox Hill Hospital in New York City in 1976.
- Eckman, Fern Marja (February 7, 1976) "Rosalie Leventritt: For Young Musicians" The New York Post
- "Mrs. Leventritt, Gave Music Prize: Foundation Organizer Dies— Encouraged Young Talent" (February 29, 1976) The New York Times, p. 47