In 1923, Lederman helped found the League of Composers in New York City, and saw the need for a music review magazine.
A number of composers wrote for the magazine, including Aaron Copland, Virgil Thomson, Elliott Carter, Leonard Bernstein, John Cage, Marc Blitzstein and Roger Sessions.
European composers were also featured, including Alban Berg, Arnold Schoenberg and Béla Bartók.
Because of the importance of the magazine, Lederman maintained considerable influence in shaping pre-World War II American music, perhaps more than any single composer.
She edited the Stravinsky in the Theater anthology[4] published in 1947 and contributed to magazines including Saturday Review, The American Mercury, The Nation and others.