European art music is largely distinguished from many other non-European classical and some popular musical forms by its system of staff notation, in use since about the 11th century.
 Catholic monks developed the first forms of modern European musical notation in order to standardize liturgy throughout the worldwide Church. Western staff notation is used by composers to indicate to the performer the pitches and durations for a piece of music. In contrast to most popular styles that adopted the song (strophic) form or a derivation of this form, classical music has been noted for its development of highly sophisticated forms of instrumental music such as the symphony, concerto, fugue, sonata, and mixed vocal and instrumental styles such as opera, cantata, and mass.
The term "classical music" did not appear until the early 19th century, in an attempt to distinctly canonize the period from Johann Sebastian Bach to Ludwig van Beethoven as a golden age. The earliest reference to "classical music" recorded by the Oxford English Dictionary is from about 1829.