Films do not have as much history as music but films do have various features which would strike the audience. When producers add soundtracks into films, they become more memorable and meaningful. I found a link about famous soundtracks from 1960s to 2000s to introduce the element of the soundtrack.
In the link above, each soundtrack is created by different purposes for films. Furthermore, each soundtrack picture is depicted within it's own film atmosphere.
There was a silent film created to show up the audience at past. As I'm a movie fan, listening to movie music is another fun way to keep the film in one's memory. Once one has watched film in theater, they would have chance to enjoy it by either watching it again or by listening to the soundtrack. The relationship between film and music is strength that makes the audience experience memorable.