Art is sometimes divided into two kinds, high art and popular art. High art attracts a much smaller population than popular art,but the number is large and growing. People who enjoy high art go to the opera and symphony concerts ; they read serious books and go to serious plays ; they keep up with art exhibitions. Popular art is mainly a kind of amusement. Some TV programs are meant to be watched today and forgotten tomorrow. Many popular songs are hits for a few weeks ; then they disappear. Other songs remain popular for such a long time that they become _ . The line between high and popular art is not always clear,however. Many people believe that rock music, for example, is a real art form. Many films are also taken seriously ,while others disappear as nothing more than amusement. According to the passage,  _   belong to popular art.
operas art exhibitions TV programs some songs popular for a short time