text: Among the largest of these is the division between classical music ( or `` art '' music ) , and popular music ( or commercial music â `` including rock music , country music , and pop music ) .
simplified: Sometimes `` classical music '' is used to mean any art music that is not `` pop music '' , but in the History of Music , the term `` classical music '' means music from the late 1700s and the first years of the 1800s .