Anything from the Carter Family would be a great choice. I am a big fan of Charlie Poole, he might fit in with your theme well. He often used popular songs of the time and Tin Pan Alley stuff. Although he died in 1931, he helped lay the foundation for the newly emerging hillbilly record business; by the time Jimmie Rodgers and the Carter Family entered the recording studios, he had already sold a quarter million records.