Searched: Combinations of "song-plugger," "history," and "women." Haven't found much besides a basic description of what a song-plugger is, and a few articles on modern-day song-pluggers.
Could a woman in her twenties get a job as a song-plugger (playing a piano in a music store in order to demonstrate sheet music) during the early twentieth century? It's all right if it would have been unusual; I just need to know if it conceivably could happen.
If it could happen, how much would it pay? Enough for her to live on?