Classical music is a broad, somewhat imprecise term, referring to music produced in, or rooted in the traditions of, European art, ecclesiastical and concert music, encompassing a broad period from roughly 1000 to the present day. The central norms of this tradition, according to one school of thought, developed between 1550 and 1825, focusing on what is known as the common practice period.
The term classical music did not appear until the early 19th century, in an attempt to 'canonize' the period from Bach to Beethoven as an era in music parallel to the golden age of sculpture, architecture and art of classical antiquity, (from which of course no music has directly survived). The earliest reference to 'classical music' recorded by the Oxford English Dictionary is from about 1836. Since that time the term has developed in common parlance as a simple opposite to popular music.
According to one school of thought, musical works are best understood in the context of their place in musical history; for adherents to this approach, this is essential to full enjoyment of these works. There is a widely accepted system of dividing the history of classical music composition into stylistic periods. According to this system, the major time divisions are:
Ancient music - the music generally before the year 476, the approxiamate time of the fall of the Roman Empire. Most of the extant music from this period is from ancient Greece.
Medieval, generally before 1450. Monophonic chant, also called plainsong or Gregorian Chant, was the dominant form until about 1100. Polyphonic (multivoiced) music developed from monophonic chant throughout the late Middle Ages and into the Renaissance.
Renaissance, about 1450–1600, characterized by greater use of instrumentation, multiple melodic lines and by the use of the first bass instruments.
Baroque, about 1600–1750, characterized by the use of complex tonal, rather than modal, counterpoint, and growing popularity of keyboard music (harpsichord and pipe organ).
Classical, about 1730–1820, an important era which established many of the norms of composition, presentation and style. Also, the classical era is marked by the disappearance of the harpsichord and the clavichord in favour of the piano, which from then on would become the predominant instrument for keyboard performance and composition.
Romantic, 1815–1910 a period which codified practice, expanded the role of music in cultural life and created institutions for the teaching, performance and preservation of works of music.
Modern, 1905-1985 a period which represented a crisis in the values of classical music and its role within intellectual life, and the extension of theory and technique. Some theorists, such as Arnold Schoenberg in his essay "Brahms the Progressive," insist that Modernism represents a logical progression from 19th century trends in composition; others hold the opposing point of view, that Modernism represents the rejection or negation of the method of Classical composition.
20th century, usually used to describe the wide variety of post-Romantic styles composed through the year 2000, which includes late Romantic, Modern and Post-Modern styles of composition.
The term contemporary music is sometimes used to describe music composed in the late 20th century through present day.
The prefix neo is usually used to describe a 20th Century or Contemporary composition written in the style of an earlier period, such as classical, romantic, or modern. So for example, Prokofiev's Classical Symphony is considered a Neo-Classical composition.
The dates are generalizations, since the periods overlapped. Some authorities subdivide the periods further by date or style. However, it should be noted that these categories are to an extent arbitrary; the use of counterpoint and fugue, which is considered characteristic of the Baroque era, was continued by Mozart, who is generally classified as typical of the Classical period, by Beethoven who is often described as straddling the Classical and Romantic periods, and Brahms, who is often classified as Romantic.