Chord zithers are produced without a fretboard to play the zither much easier. They are usually played with sheet of music put under it. These kind of strings are divided into two categories: one set of strings is tuned to the diatonic and the other set is tuned to make the various chords in the principal key of the melody strings. The ‘Piano Harp’ (right) has six chords, making the accompanimet easier. These Guitar Zithers are played by using a plectrum specific to zither. The ‘Autoharp’ (middle, left) is another type of this kind. It consists of 5 respectively 6 chord bars attached to dampers, when depressed, mute all of the strings other than those that form the desired chord. This instrument was invented by August Gütter from Markneukirchen in 1870. C.f. Zimmermann from the same region took this zither to America where it became a popular instrument in the first half of the 20th century.
