String instruments produce sound by way of a string stretched between two points. Players bow, pluck or strike the string to produce vibrations, which in turn produce the sound. String instruments are used in a wide variety of settings and in a wide variety of music genres, from symphony orchestras to a country music.
The most prominent group of stringed instruments are those of the violin family, whose members are the violin, the viola, the violoncello--usually just called the cello--and the double bass.
The viol family is a group of instruments developed during the Renaissance. These differ from the violin family in that they have flat backs, frets and six strings.
Plucked String Instruments
Plucked string instruments are played by plucking, picking or strumming, and have many examples, including the guitar, banjo, oud, harp and the harpsichord, which is a keyboard instrument.
Struck String Instruments
Struck stringed instruments, which produce sound when something such as mallet or hammer strikes a string, include well-known instruments such as the piano, and lesser-known instruments such as the hammered dulcimer and the cimbalom, a Hungarian instrument used for classical, folk and gypsy music.
Because the piano has strings, it is considered a string instrument, but the instrument is also considered a percussion instrument because the strings are struck by hammers.
The aeolian harp is a struck type of stringed instrument that is played by the wind, the strings being "struck" as the air blows--no human is needed except to appreciate the music created by nature.