The term 'Dulcimer Cousins' refers to two stringed instruments, the dulcimer and the zither. The dulcimer is a fretted string instrument of the Appalachian region of the United States, while the zither is a stringed instrument with a flat soundboard that is popular in many European countries. Both instruments are played by plucking or strumming the strings with the fingers or a pick. The zither has seven letters, making it one of the dulcimer's cousins.