William Schuman (1910–92) made an influential contribution to American musical life as composer, teacher, and administrator. He was born in New York City and began serious study of music relatively late. He once explained: “It was not a matter of my being interested in baseball in my youth. It was my youth.” That essentially American sport gave him the subject of his only opera, The Mighty Casey, but he was energetically involved in various types of popular music and jazz at a time when his composer contemporaries were studying abroad. Schuman wrote songs with Edward B. Marks Jr. and Frank Loesser before they became household names, but the turning point came when he heard Toscanini conduct the New York Philharmonic in 1930. Schuman was nineteen and had reluctantly accompanied his sister to the concert. It changed his life and enabled him to recognize his future. He abruptly left his courses at the School of Commerce at New York University, but he never lost his business sense. The experience of seeing and hearing a large orchestra fueled his enthusiasm for the symphony in a way that carried through into his own substantial contributions to the form.

In the early 1930s Schuman gradually became a serious composer, but his melodic style was permanently affected by his work in popular song. Later he said that he wrote entirely by singing, not by sitting at the piano. His studies included summer courses at the Juilliard School of Music, of which he was later president, and—after he came across the Third Symphony—studies with Roy Harris. Schuman completed two degrees at Columbia University Teachers College and in 1935 took a teaching post at Sarah Lawrence College. Already, his separate strands of composer, educator, and visionary planner began to interact. He was able to try out his theories on the students, especially the notion of teaching music from actual music rather than using mere academic models.

In 1938 Schuman's Second Symphony attracted the attention of Koussevitzky, who conducted it with the Boston Symphony, although Schuman later withdrew the work. In 1941 his Third Symphony won the first New York Music Critics Circle Award, and the following year his choral work A Free Song earned the first of his two Pulitzer Prizes. In 1943 his Fifth Symphony, for strings, was acclaimed; these successes quickly established Schuman's reputation.