In this section, the instruments that will be listed are the instruments that play a main part in an orchestra. Those instruments being the violin, viola, cello, and contrabass.
The violin is a wooden chordophone. It has a hollow, wooden, body and is the smallest and highest pitched instrument in it's family. Violins are important instruments in a wide variety of musical genres. They are most prominent in the Western classical tradition, both in ensembles (from chamber music to orchestras) and as solo instruments. Violins are also important in many varieties of folk music, including country music, bluegrass music and in jazz.
The viola is a string instrument that is bowed, plucked, or played with varying techniques. It is slightly larger than a violin and has a lower and deeper sound. The viola was popular in the heyday of five-part harmony, up until the eighteenth century, taking three lines of the harmony and occasionally playing the melody line. Music for the viola differs from most other instruments in that it primarily uses the alto clef. The viola often plays the "inner voices" in string quartets and symphonic writing, and it is more likely than the first violin to play accompaniment parts. The viola occasionally plays a major, soloistic role in orchestral music.
The cello or violoncello is a bowed string instrument of the violin family. Its four strings are usually tuned in perfect fifths: from low to high, C₂, G₂, D₃ and A₃. Each string is an octave lower than the viola's four strings. It enjoys a large solo repertoire with and without accompaniment, as well as numerous concerti. As a solo instrument, the cello uses its whole range, from bass to soprano, and in chamber music such as string quartets and the orchestra's string section, it often plays the bass part, where it may be reinforced an octave lower by the double basses. Figured bass music of the Baroque-era typically assumes a cello, viola da gamba or bassoon as part of the basso continuo group alongside chordal instruments such as organ, harpsichord, lute or theorbo.
The contrabass, also known as the double bass and simply as the bass, is the largest and lowest-pitched bowed string instrument in the modern symphony orchestra. The bass is a standard member of the orchestra's string section, as well as the concert band, and is featured in concertos, solo, and chamber music in Western classical music. The bass is used in a range of other genres, such as jazz, 1950s-style blues and rock and roll, rockabilly, psychobilly, traditional country music, bluegrass, tango and many types of folk music.
