Originally, chamber music referred to a type of classical music that was performed in a small space such as a house or a palace room. The number of instruments used were also few without a conductor to guide the musicians. Today, chamber music is performed very similarly in terms of the size of the venue and the number of instruments used. Typically, a chamber orchestra is composed of 40 or fewer musicians. Because of the limited number of instruments, each instrument plays an equally important role. Chamber music differs from a concerto or a symphony because it is performed by only one player per part.
Chamber music evolved from the French chanson, a vocal music comprising of four voices accompanied by a lute. In Italy, the chanson became known as canzona and evolved from its original form of vocal music into instrumental music often adapted for the organ.
During the 17th century, the canzona evolved into the chamber sonata performed on two violins plus a melody instrument (ex. cello) and harmony instrument (ex. harpsichord).
From the sonatas, specifically the trio sonatas, (ex. works by Arcangelo Corelli) evolved the string quartet which uses two violins, a cello and viola. Examples of string quartets are works by Franz Joseph Haydn.
In 1770, the harpsichord was replaced by the piano and the latter became a chamber music instrument. The piano trio (piano, cello and violin) then emerged evident in the works of Wolfgang Amadeus Mozart, Ludwig van Beethoven and Franz Schubert.
In the late 19th century, the piano quartet (piano, cello, violin and viola) emerged with the works of such composers as Antonín Dvorák and Johannes Brahms. In 1842, Robert Schumann wrote a piano quintet (piano plus string quartet).
During the 20th century, chamber music took on new forms combining different instruments including the voice. Composers such as Béla Bartók (string quartet) and Anton von Webern contributed to this genre.