Although the art song was a favorite genre for American composers at the turn of the twentieth century, its favor declined rapidly and significantly during and after the 1910s, and for the rest of the first half of the century the genre held a marginalized place in the output of the most significant American composers. Concomitant with this decline in song composition, song publication also declined considerably after 1920, and a significant percentage of the songs published thereafter were authored by composers who specialized in songs and shorter works expressly intended for the domestic song market and written in a conservative musical idiom which appealed to mass audiences. In contrast to these earlier declines, the number of song concerts in New York City and Chicago increased steadily until about 1930, even as the percentage of song concerts to other concerts held steady. After 1930, however, the number and percentage of song concerts in these two cities declined as well. The emergence of modernism on the musical landscape in the United States after 1915 was largely responsible for the decline in song publication and composition. Among other things, musical modernism valorized dissonance, melodic fragmentation, and objectivity; these characteristics ran counter to the largely Romantic orientation of the art song with its long-spun lyricism and subjectivity. As a revision of current thought, this study broadens the accepted corpus of modernist composers to include neo-Romantics such as Samuel Barber whose music retained an essentially Romantic character but was frequently imbued with modernistic elements. This study also shows that composers in certain stylistic, professional, and demographic categories wrote songs in significantly greater numbers those in others. For example, in looking at the total song output of over 100 American and transplanted composers, there was a direct correlation between musical style and song production; the more progressive a composer's musical style, the fewer songs he authored. In addition to the impact of modernism on the art song, these declines were also exacerbated by the art song's close association with other song types which lowered the art song's aesthetic credentials.