Walt Whitman's poems inspired him to write the symphony, and Whitman's use of free verse became appreciated at a time where fluidity of structure was becoming more attractive than traditional, metrical settings of text.
Os poemas de Walt Whitman inspirárono para escribir a sinfonía, e o uso de verso libre de Whitman tornouse apreciado nun momento no que a fluidez da estrutura se volveu máis atractiva que os tradicionais axustes métricos do texto.