The harmonica, that most modest of instruments, has ancestors that go back to Asia over a thousand years ago. But the "mouth organ" or "harp" as we know it today dates back only to 19th century Germany. In 1822 an inventor and musician from Berlin named Christian Bauschmann made an experimental instrument with fifteen reeds called the aura, designed mainly as a pitch pipe. It attracted the attention of a local clockmaker named Christian Messner. Because of an economic depression, the clock business was bad and Messner was looking for other ways to make a living. He started making cheap copies of the aura to peddle at local fairs and carnivals, and soon other German craftsmen were getting into the act. Then, in 1857, Matthias Hohner figured out how to mass-produce the little instruments, and soon became the leader in the field. By 1977 he was making over 700,000 harmonicas a year, and over half of them were being exported to America.
Sears Catalog 1912
Americans seem to have taken the harmonica to heart from the very first. They were carried by soldiers in the Civil War, and by1890 were being sold mail order by dozens of catalogue stores. Though the harmonica was one of the few instruments that could not be home-made and harmonica sellers offered instruction books about the "proper" way to play, Americans quickly began to explore unorthodox ways of playing.
Blues musicians learned how to cup their hands over the harmonica to get all kinds of bent and slurred notes; others would "choke" the instrument to get odd, percussive effects. White musicians liked to try the imitations of chickens or trains or a fox hunt.
Harold Courlander, an early collector of African American folk music, has called the harmonica "probably the most ubiquitous of Negro folk instruments." It was featured as a solo instrument by pioneers like Grand Ole Opry star DeFord Bailey, and by Arkansas radio pioneer Sonny Boy Williamson. As the blues moved to Chicago, the harmonica became the major accompaniment for stars like Muddy Waters.