Another idea I had is music used in movies as many popular songs and soundtracks can be linked back to a movie such as big instrumental songs, most commonly John Williams' big orchestral songs such as Star Wars:
And Jurassic Park:
And singles written for a film such as all James Bond themes:
To songs already made but a movie bring it back to the spotlight such as Blue Swede's Hooked on a Feeling used in Marvel's Guardians of the Galaxy:
If I want to do discrimination then a good first film to focus on is Suffragettes due to the message of the film and also the controversy surrounding the premier of the film.
My main focus for my research is to do with actors in some form. I found an interesting article about the Oscars and the lack of diversity. Discrimination has always been around in Hollywood in some form and the subject interests me as I wonder how it is still such a big thing and why there has been little to do to stop it! http://variety.com/2016/biz/news/oscar-nominations-2016-diversity-white-1201674903/