Classical music is art music produced or rooted in the traditions of Western music (both liturgical and secular). It encompasses a broad span of time from roughly the 11th century to the present day. The central norms of this tradition became codified between 1550 and 1900, which is known as the common practice period. The major time divisions of classical music are as follows: the early music period, which includes the Medieval (500–1400) and the Renaissance (1400–1600) eras; the Common practice period, which includes the Baroque (1600–1750), Classical (1750–1830), and Romantic eras (1804–1910); and the 20th century (1901–2000) which includes the modern (1890–1930) that overlaps from the late 19th-century, the high modern (mid 20th-century), and contemporary or postmodern (1975–present) eras.
European music is largely distinguished from many other non-European and popular musical forms by its system of staff notation, in use since about the 16th century. Western staff notation is used by composers to prescribe to the performer the pitch, speed, meter, individual rhythms and exact execution of a piece of music. This leaves less room for practices such as improvisation and ad libitum ornamentation, which are frequently heard in non-European art music and in popular music. Another difference is that whereas most popular styles lend themselves to the song form, classical music has been noted for its development of highly sophisticated forms of instrumental music.