Popular music is by definition music that is disseminated widely. As such, it has been particularly significant with the twentieth-century proliferation of recording technologies and mass media. Sometimes we may forget that it was not until the 1920s that recording and playback technology allowed for the spread of music through records. To become popular before that time, a tune had to be spread by word of mouth, by traveling performers, and by music notation, which might ap- pear in a music magazine or newspaper or in sheet music that could be bought at general stores, catalogs, and music stores.
Today the success of a popular music artist is most often measured by how many songs they sell. In the past, that meant record and CD sales, but today it essentially means numbers of downloads. Recording industry executives determine which artists to record and distribute based almost entirely on their perceived ability to sell units. Most popular music today is sold by downloading it to an electronic device, though CDs are still manufactured and distributed.
Popular music is also often thought of as ephemeral, that is, as remaining in the consciousness of a group of people for a limited time. For this chapter, we have chosen popular music that has either transcended that boundary or that was so important in or exemplary of its time and place that its discussion helps us understand music, history, and culture more broadly. It is, however, but a sampling of a huge body of popular music that exists in the United States since roughly the Colonial period. As you listen to these examples, perhaps you can think of similar examples of popular music that you know.