How Stringed Instruments Work
Some of the simpler instruments are the string instruments. String instruments make sound with vibrating strings, and the pitch is modified by the thickness, tension, and length of the string. String instruments can be played in many ways, and come in many variations. String instruments range from the simple lyre, to the modern guitar, violin, and piano. All rely on the sound of strings.
All string instruments make sounds with tensioned strings. Longer strings produce a lower tone than shorter ones. Tighter strings produce a higher sound than looser ones. Thicker strings produce a lower sound than thinner strings. That is why, even though all the strings on a guitar are the same length, they all sound a different note. String instruments can be plucked, bowed, or in the case of the piano, struck. Bowing allows very long, sustained notes with interesting dynamics. Electric guitars use magnetic pickups to convert vibration to an electric signal. String instruments must be tuned perfectly by tightening or loosening their strings.
Playing Different Notes
Different notes are produced in different ways by string instruments. Instruments like the zither, harp, and piano have sets of parallel strings, one for each note, that can be sounded individually, or together to make chords. Instruments like the guitar or violin use the fingers to lengthen or shorten the lengths of strings, to produce different pitches. You can try with this imaginary one-stringed, four-fret guitar. Just click on a fret to see how it affects the pitch.