Can anyone give me a song about injustices and cruelty associated with class distinctions?

I asked a question similar to this last year and got an amazing response so I was wondering if you guys could help me once more.

For my English class I have a story project on “The Doll’s House” by Katherine Mansfield. For the project I want to find a song that represents the theme of the story for my presentation next week. The theme is one of how class distinctions separate people even though there isn’t anything else that should separate them. Just because the groups of people come from different classes (one rich and the other poor) they can not have contact with each other despite possibly being friends. The world finds it to be horrible and is cruel to them for being together.

Although that’s a rough explanation you can get a better meaning of what I said if you read the short story which you can find here:

http://www.lamaquinadeltiempo.com/mansfield/04dollh.htm

I’d be very grateful if you guys could help me here.