Songwriters Calhoun and Harrigan get Katie and Lily Blane to introduce a new song. Katie joins Lily in England after the boys give their latest song to Nora Bayes. All are reunited after the boys, now in the army, show up in England.

From the late 19th century into the 20th century, an area of New York City nicknamed Tin Pan Alley was the heart of the American popular music scene. In this hotbed of creativity, singing sisters Katie and Lily Blane team up with musicians Harry Calhoun and Skeets Harrigan to find their fame and fortune. Romance soon follows, but the rocky road to success and the looming World War I threaten to tear the couples apart.—Jwelch5742

In 1915, Calhoun and Harrigan are struggling songwriters who team up with vocal talents Katie and Lily Blane. With the Blanes singing their songs, the writers become more prosperous and famous. Harrigan and Katie Blane become romantically involved and he writes "America, I Love You" which he promises she can introduce to the world. When the world-famous Nora Bayes asks to sing Katie's song, Harrigan cannot refuse. Upset at the broken promise, Katie leaves for London along with her sister. As their prosperity fades without the singers, the two men enlist in World War I and run into the sisters in England.—Paul Donahue