Violin: The violin is a bowed, stringed musical instrument that evolved during the Renaissance from earlier bowed instruments: the medieval fiddle; its 16th-century Italian offshoot, the lira da braccio; and the rebec. The violin is probably the best known and most widely distributed musical instrument in the world. Like its predecessors but unlike its cousin the viola, the violin has a fretless fingerboard. Its strings are hitched to tuning pegs and to a tailpiece passing over a bridge held in place by the pressure of the strings. The bridge transmits the strings' vibrations to the violin belly, or soundboard, which is made of pine and amplifies the sound. Inside the instrument, beneath the treble foot of the bridge and wedged between the violin belly and back, which is made of maple, is the sound post, a thin stick of pine that transmits the string vibrations to the instrument's back, contributing to the characteristic violin tone. The belly is supported from beneath by the bass bar, a narrow wood bar running lengthwise and tapering into the belly. It also contributes to the resonance of the instrument. The sidewalls, or ribs, are constructed of pine-lined maple. The violin was early recognized for its singing tone, especially in Italy, its birthplace, where the earliest makers--Gasparo da Salò, Andrea Amati, and Giovanni Paolo Maggini--had settled its average proportions before the end of the 16th century. During its history the violin has been subject to modifications that have progressively adapted it to its evolving musical functions. In general, the earlier violins are more deeply arched in the belly and back; the more modern, following the innovations of Antonio Stradivari, are shallower, yielding a more virile tone. In the 19th century, with the advent of large auditoriums and the violin virtuoso, the violin underwent its last changes in design. The bridge was heightened, the sound post and bass bar were thickened, and the body became flatter. The neck was angled back, giving greater pressure of the strings on the bridge. The result was a stronger, more brilliant tone in place of the delicate, intimate tone of the violin of the 18th century. The earliest violins were used for popular and dance music. During the 17th century it  replaced the viol as the primary stringed instrument in chamber music. The Italian composer Claudio Monteverdi included violins in the orchestra of his opera Orfeo (first performed in 1607). In France the king's orchestra, les 24 violons du roi, was organized in 1626. Arcangelo Corelli, a virtuoso violinist, was among the earliest composers to contribute to the new music for the violin, as did Antonio Vivaldi, J.S. Bach, and the violinist Giuseppe Tartini. Most major composers from the 18th century on wrote solo music for the violin, among them Mozart, Beethoven, Robert Schumann, Johannes Brahms, Edvard Grieg, Paul Hindemith, Arnold Schoenberg, and Alban Berg. Such virtuosos as Francesco Geminiani, Niccolò Paganini, Joseph Joachim, Fritz Kreisler, David Oistrakh, Yehudi Menuhin, and Isaac Stern stimulated the composition of fine violin music. The violin was assimilated into the art music of the Middle East and South India and, as the fiddle, is played in the folk music of many countries. The tenor violin, known from the 16th century through the 18th century, was midway in size between the viola and cello. It was tuned F-c-g-d'. "Tenor violin" also occasionally referred to the viola.
 

Viola: The viola is stringed musical instrument, the tenor of the violin family. It is built in proportions similar to those of the violin but has a body length of 37 to 43 centimetres (14.5 to 17 inches), about 5 cm (2 inches) longer than a violin. Its four strings are tuned c-g-d'-a', beginning with the C below middle C. The viola's tone is darker, weightier, and warmer than that of the violin. The modern symphony orchestra contains from 6 to 10 violas. The viola is an integral member of the string quartet and larger chamber music ensembles. In the 18th-century orchestra the viola usually doubled cello parts. Christoph Willibald Gluck, Wolfgang Amadeus Mozart, and Joseph Haydn gave it distinctive treatment, and it gradually assumed an independent orchestral role. Hector Berlioz included a long viola solo in his Harold in Italy; in Richard Strauss's Don Quixote the viola carries the theme of Sancho. The viola also gained in prominence through the viola sonatas of Paul Hindemith, Béla Bartók's viola concerto, and violists such as William Primrose and Walter Trampler. It was frequently used in 20th-century chamber music ensembles (e.g., by: Arnold Schoenberg and Pierre Boulez). The viola d'amore is a viol-violin hybrid played like a violin. It is of 18th-century origin, has six or seven melody strings and several sympathetic strings, and is unfretted. A 17th-century violin with five wire strings was also called viola d'amore. The viola da braccio, or viola da brazzo (Italian: "arm viol"), was the original name for violin-family instruments, in contrast to the viola da gamba ("leg viol"), or viol, family.
 

Cello: The cello, also called Violon Cello, French Violoncelle, German Cello, or Violon Cello, bass musical instrument of the violin group, with four strings, pitched C-G-D-A upward from two octaves below middle C. The cello, about 27 1/2 inches (70 cm) long (47 inches [119 cm] with the neck), has proportionally deeper ribs and a shorter neck than the violin. The earliest cellos were developed during the 16th century and frequently were made with five strings. They served mainly to reinforce the bass line in ensembles. Only during the 17th and 18th centuries did the cello replace the bass viola da gamba as a solo instrument. During the 17th century the combination of cello and harpsichord for basso continuo parts became standard. Joseph Haydn, Mozart, and later composers gave increased prominence to the cello in instrumental ensembles. Notable works for the instrument include J.S. Bach's six suites for unaccompanied cello, Beethoven's five sonatas for cello and piano, the concertos of Antonín Dvorák and Zoltán Kodály, and the Bachianas brasileiras of Heitor Villa-Lobos, for eight cellos and soprano. One of the
outstanding cellists of the 20th century was Pablo Casals.
 

Bass: The bass, in music, the lowest part in a multi-voiced musical texture. In polyphony of the sort that flourished during the Renaissance, the bass formed one of several relatively independent or contrapuntal melodies. During the figured-bass era (17th and early 18th centuries), the thorough bass, or basso continuo, furnished a "base" for accompaniments played with relative freedom, though bound by certain conventions as well as shorthand instructions inserted in figures above the bass. In the homophonic, basically chordal, musical styles of the later 18th and 19th centuries, the bass was of crucial structural significance as the lowest of parts and, thus, the foundation of harmony. In vocal music, the bass is the lowest male voice, with a typical range from the second E below middle C to F above; the basso profundo is low and rich, while the basso cantante ("singing bass") is lighter and more lyric. Among instruments, the lowest-pitched member of a family is referred to as the bass, for example, the bass recorder or bass viol. The lowest-pitched member of the violin family is called a double bass.
 

Double Bass: The double bass also called Contrabass, String Bass, Bass, Bass Viol, Bass
Fiddle, or Bull Fiddle, French Contrebasse, GermanKontrabass,is a stringed musical instrument, the lowest-pitched member of the violin family, sounding an octave lower than the cello. It has two basic designs--one shaped like a viol (or viola da gamba and the other like a violin--but there are other designs, such as that of a guitar. It varies considerably in size, the largest normally being under 6 feet (1.8 metres) in total length. The body itself, without the neck, may be up to 4.5 feet (1.4 metres) for a full-size instrument, about 3.8 feet (1.15 metres) for a three-quarter size, and only slightly larger than a cello for the small chamber bass, or bassetto. A double bass is usually strung with four heavy strings pitched E1-A1-D-G; a fifth string is occasionally added--in jazz band basses, at the top of the register to allow high notes to be played more easily; in symphony orchestra basses, below the E string, tuned to C. Many basses, rather than having a fifth string, lower the compass by an extension to the E string that runs along the scroll at the end of the neck. The string is either provided with keys that sound E, D, D, and C or clamped to sound E when the lower notes are not needed. Two styles of bass bow are currently used: the short and narrow French bow (like a violin bow), held palm downward, and the broader German bow (like a viol bow), held palm upward. The double bass is also played pizzicato (by plucking with the fingers)--occasionally in symphonic orchestras and almost always in jazz and dance bands. Forms of the double bass date from the late 15th or early 16th century and were in common use by the 18th. Ludwig van Beethoven and later composers gave the bass increased importance in the symphony orchestra. Beethoven's friend Domenico Dragonetti and the conductor Serge Koussevitzky, both skilled bassists, composed concertos for the instrument. In jazz ensembles the bass forms part of the rhythm section and is also used as a melody instrument.