Classical music is the art music produced in, or rooted in, the traditions of Western liturgical and secular music, encompassing a broad period from roughly the 9th century to present times. The central norms of this tradition became codified between 1550 and 1900, which is known as the common practice period. 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.