The violin is the soprano member of the violin family of string instruments. It is held horizontally with the bottom end of the resonator (as viewed in the picture at the left) pinched lightly between the player's left shoulder and chin so that the top face of the resonator is facing upwards. Its four strings, made of steel wire (for the highest-pitched string) or wire-wound gut (for the other three strings), are stretched over a waisted wood resonator and a neck with a fretless fingerboard. The tension of each individual string is adjusted with a tuning peg that is mounted in the peg box at the end of the instrument's neck. The violin pictured at left has an additional fine-tuning device for its highest string located where that string comes in contact with the instrument's tailpiece. A high, thin bridge situated on the upper face of the instrument's body transmits energy from the vibrating strings to the resonating chamber; this transmission is further aided by a wood sound post that is wedged between the upper and lower faces of the resonator, exactly below the bridge. Sound escapes from the resonating chamber via the two f-shaped sound holes carved into its upper face. The strings are generally set into vibration with a rosined horsehair bow, although they are sometimes plucked (called pizzicato) instead. The performer uses the fingers of her/his left hand to alter the lengths of the strings by pressing them against the fingerboard, thus producing numerous pitches on any given string. By lightly touching, instead of pressing, the strings at key points, the harmonics of a string's fundamental pitch are produced. The basic timbre of the instrument can be subdued by placing a comb-shaped mute over the instrument's bridge. The violin developed from a variety of other string instruments into a form recognizable to us today in sixteenth century Italy (see Close-ups: Then and Now--The Violin). Its lowest string is tuned to G below middle C, with the other strings successively tuned an interval of a fifth above the preceding one. Because the neck of the instrument has no frets, the performer can produce either chromatic intervals or microtonal ones over the violin's entire four-octave range. A vast repertoire of solo (unaccompanied, sonata and concerto) literature exists for the violin. It is a mainstay both of the orchestra and of string and piano-and-string chamber music.

Musicians from genres outside of the classical music establishment and from a variety of music cultures around the world have adapted the violin to their traditions--folk fiddling, bluegrass, country and western, jazz (listen to the second audio example on this page), Mexican mariachi, European Gypsy, Yiddish Klezmer, South Indian classical music, and many others.