Zither is a stringed musical instrument, which was most common in Austria and Germany in the 18th century. It has a flat wooden body of irregular shape, and from 30 up to 45 strings (depending on the size of the instrument). Several strings (usually 4-5) closest to the performer, stretched across the fretboard with metal frets, are plucked with a plectrum worn on the thumb of the right hand. They are used to play the melody. The remaining strings are used for chord accompaniment and are played with other fingers. Western Europeans are familiar with zither since the end of 18th century, in Russia it is known since second half of 19th century. Similar instruments of ancient origin are found among many nations. For example, zithers were common in China and the Middle East.