The autoharp is a beautiful sounding stringed folk instrument made popular as a parlor solo instrument in America during the latter part of the 19th century and early 20th century. It was one of the fundamental instruments in much of the music played by Mother Maybelle and Sara Carter of the original Carter Family in the 1920's. Many folks believe that the autoharp was truly an American invention of Charles F. Zimmerman of Philadelphia taken from an 1871 patent. However, in reality, though Zimmerman made some innovative improvements, the autoharp was originally invented in Germany by Karl August Guther where it was known as the "Folkszither". The autoharp is actually related to the zither which is a multiple string instrument whose strings of different length correspond to the notes of the scale (e.g., diatonic or chromatic), as in a piano. However, the strings on a zither are stretched between two bridges, mounted to a wooden base, and plucked with the fingers to produce the desired notes or groups of notes. The zither can be played on a table (or lap) or held upright against the chest. In an autoharp, the principal difference is a mechanical device that overlies all of the strings along one of the bridges. This device contains rows of buttons labeled specifically to correspond to different chords. When the artist depresses a particular button, specific strings are muted and the remaining strings produce the sound of a full chord when strummed. Unlike the zither, beautiful chord melodies can be very easily played with the autoharp providing a fuller dynamic melodic and rhythmic richness for the solo performer. Most harpists plays a "chromatic" autoharp to allow maximum flexibility in key changes. People who like to play traditional tunes and lyrical chord melodies prefer this kind of autoharp.