JuilliardThe term chamber music is usually applied to concert pieces performed by one to nine instrumentalists, as distinguished from orchestral or band music, which is played by considerably larger groups, or from solo keyboard music, which is regarded as a separate genre. Chamber music gets its name from the practice of playing it indoors, in a chamber or room, rather than outdoors, as one might expect with a brass band. When the term was coined around the middle of the 16th century, the specific chambers referred to were the drawing rooms of wealthy European aristocrats, whose private concerts were described as musique de chambre, musica da camera, or Kammermusik. At this early stage, much chamber music was played from parts written for voices or semi-improvised. Viol consorts, small orchestras made up of string players, were common in England and Spain well into the 17th century.
 
CorelliIt wasn't until the dawn of the Baroque era, around 1600, that composers began to create a repertoire specific to the needs of small, domestic ensembles. The introduction of the figured bass accompaniment, plus that of solo instrumental works, two-voice canzonettas, and solo cantatas with continuo, helped direct chamber music into a common enterprise. Toward the beginning of the 18th century, publishers began to recognize a trend: the trio sonatas of Arcangelo Corelli (right) are often cited as the first major milestone in the publication of chamber music. The popularity of these pieces was widespread throughout continental Europe, and it helped establish the trio sonata as a major form of chamber music within the late-Baroque period. Most composers of any note, active from 1700 to 1750 (for example Antonio Vivaldi and Johann Sebastian Bach), composed sets of sonatas for publication in order to feed the growing market. Certain works of Georg Philipp Telemann, such as his Tafelmusik (1733), stand out as excellent examples of this development, in addition to placing the specific purpose of the pieces within the context of domestic music-making.
 
HaydnAs the Classical era began in earnest, chamber combinations proved well-suited to the projection of the emerging style galant, which emphasized a clear-cut approach to melody and simple, elegant accompaniment. The next major phase in chamber music occurred around 1758 when Austrian composer Franz Joseph Haydn (left) began composing string quartets. Although Telemann and a few others developed works from about 1730 that consisted of two violins, viola, and cello, the String Quartets, Op. 1 of Haydn, published by Bremner in 1766, were widely disseminated throughout Europe and helped fuel the string quartet craze of the later 18th century. Initially, the first violin part carried the majority of the melodic material while the other parts followed along, filling in the harmony. French quartet composers of the 1770s began to favor a more independent treatment of the individual voices; both Haydn and his ardent admirer Wolfgang Amadeus Mozart followed suit. Although the string quartet remained the primary chamber ensemble of the Classical era, some wind bands began to shrink in size and come indoors, as well. Dubbed "Harmoniemusik," these small five- and six-piece bands were the first chamber-sized woodwind groups, often playing medleys of arias from popular operatic music of the day, or in divertimenti, suites of short pieces designed to be played during dinnertime. Some of Haydn's early quartets were entitled cassations (another term meaning divertimenti) upon their initial publication.
 
Müller Brothers QuartetAs the Classical era gave way to the Romantic period around 1810, the string quartet held its ground as chamber works became longer and more serious in tone than their predecessors. Ludwig van Beethoven chose the quartet medium in which to execute his latest and most advanced musical ideas, and this helped elevate the quartet in the minds of composers as an important challenge that needed to be met with everything one had. This became particularly important as chamber music by this time was finally growing away from its established base as a private or courtly type of music-making. The Müller Brothers Quartet (right), founded in 1835, was the first professional string quartet, and throughout Europe societies were formed to foster the public performance of chamber music. Around this time, chamber music was increasingly cast in larger instrumental groups, as in Franz Schubert's quintets, Felix Mendelssohn's Octet, Op. 20, and the Nonet, Op. 31 of Louis Spohr.
 
BrahmsThe late Romantic period was heavily invested in the large forms of opera and symphony, and in a sense this was a threat to the continued relevance of chamber music, along with the gradual disappearance of the European court that had supported its initial development. Some composers held out against the tide, in particular Johannes Brahms (left), who was most comfortable expressing himself in chamber forms. Brahms' close friend, violinist Joseph Joachim was in accord with Brahms on this point, and the former led the Joachim Quartet, likely the greatest string quartet of the 19th century. Among other key composers of chamber music in the era included Antonin Dvorak and César Franck; the violin and piano duo of Eugène Ysaÿe and Raoul Pugnio helped establish the duet format as a force to be reckoned with in recitals. Schubert's magnificent quartets and quintets gradually become known after 1860, and seemed "new" at the time. Nonetheless, the late-Romantic period was a time of eclipse for chamber music, apart from the popularity of domestic music-making among amateurs. Much of the music composed and published to support such activity was mass-produced and was neither challenging to the players nor terribly imaginative musically.
 
BartókWith the dawn of the 20th century there was an explosion of interest in chamber music among serious composers. Modernist musicians reacted strongly against the excesses of Romantic music and its frequent reliance on large instrumental forms. Thus, chamber music provided an ideal outlet for modernist expression. Many of the core works for string quartet, including important masterpieces by Claude Debussy and Maurice Ravel, the landmark cycle of six string quartets by Béla Bartók (right), Charles Ives's String Quartet No. 2, Igor Stravinsky's Three Pieces, and Anton Webern's Five Movements, Op. 5, were all written between 1900 and 1940. These works were far too difficult for amateur players and were purposefully written to expand the skills of virtuoso musicians.
 
SchoenbergArnold Schoenberg (left) introduced the modern concept of a chamber orchestra with his Chamber Symphony No. 1 in E major, Op. 9 (1906). Uncommon combinations of instruments were formed into chamber groups, for example violin, clarinet, and piano (Ives' Largo, Bartók's Contrasts), or clarinet, saxophone, violin, and piano (Webern's Quartet, Op. 22) became more frequently employed after 1900. In the mid-'30s composer Paul Hindemith instituted a series of solo sonatas for each major instrument in the orchestra, including the bassoon, tuba, and other secondary types of Western instruments. By the 1940s some Western composers, such as Alan Hovhaness and Henry Cowell, began to write pieces where non-Western instruments can be used in place of familiar instruments.
 
ShostakovichThe fifteen string quartets of Dmitri Shostakovich (right) left the most profound and enduring mark on mid-20th century chamber music. Yet the period also witnessed the rise of international serialism, and atonal, sparsely textured music derived from serial procedures was often cast in mixed instrumental groups. The instrumental duo consisting of a live player accompanied by an electronic part on tape likewise emerged mid-century. Domestic chamber music-making, which had continued up to the start of World War II, began to decline sharply afterward, and during the war many of the best professional European ensembles were forced to flee to America in order to escape Nazi oppression. As opportunities for practicing domestic chamber music declined, specialized workshops and festivals, such as the Marlboro Music Festival and the Cabrillo Music Festival, became more commonplace. The aspiring chamber performer after 1970 had better "chops" and was more competitive than a musician in 1920, but had considerably less experience sharing music played with friends or relatives.
 
Kronos QuartetIn the early stages of the contemporary period, as general interest in avant-garde music began to decline in the 1980s, record companies specializing in new music began to rely heavily on pieces written for chamber ensembles, as these could be recorded cheaply. New music specialists such as the Kronos Quartet (left) crossed genres to build an audience as familiar with rock music as it was acquainted with classical. Later years also witnessed the rise of "superstar" performances of core classics, chamber arrangements of classic rock, and the bluegrass-styled chamber performances of Yo-Yo Ma, Edgar Meyer, and Mark O'Connor. In the big picture it is clear that chamber music is more important to the continuation of the classical tradition than ever. For composers, however, the marketing of star performers is a double-edged sword, as postmodern chamber groups and instrumentalists tend to be better known than the composers whose works they play. Likewise, one wonders if the efforts of ensembles such as Bang on a Can, are representative of a new wave of chamber music or something else entirely. Only time will tell.