This article examines the popularization of “mass songs” among Chinese Communist troops during the Anti-Japanese War by highlighting the urban origins of the National Salvation Song Movement and the key role it played in bringing songs to the war front. The diffusion of a new genre of march songs pioneered by Nie Er was facilitated by compositional devices that reinforced the ideological message of the lyrics, and by the National Salvation Song Movement. By the mid-1930s, this grassroots movement, led by Liu Liangmo, converged with the tail end of the proletarian arts movement that sought to popularize mass art and create a “music for national defense.” Once the war broke out, both Nationalists and Communists provided organizational support for the song movement by sponsoring war zone service corps and mobile theatrical troupes that served as conduits for musicians to propagate their art in the hinterland. By the late 1930s, as the United Front unraveled, a majority of musicians involved in the National Salvation Song Movement moved to the Communist base areas. Their work for the New Fourth Route and Eighth Route Armies, along with Communist propaganda organizations, enabled their songs to spread throughout the ranks.  Keywords: Anti-Japanese War, Li Jinhui, Liu Liangmo, Lü Ji, Mai Xin, mass song, National Salvation Song Movement, New Fourth Army, Nie Er, United Front, Xian Xinghai Related audio-visual links: “Original film performance of “March of the Volunteers”“Jiuguo junge”“Youjiduige”“Zai Taihangshan shang”“People’s Liberation Army March” “New Fourth Army Anthem”