I'm sorry, but this is cute. People in the subway with their rap music on an obnoxiously loud volume are completely apathetic toward others. They don't care about the way other people feel about what they like, in fact, they believe it's the best thing since sliced bread...apparently.
I was raised to know that it's a common courtesy to keep your volume down to a quiet level any time you're in a public place so that others can hear official announcements and directions from authorities. I blame the parents of people who listen to their music loudly like this as failures to the rest of society. They should have taught/disciplined their children better.
Instead, I've coped simply by having earbuds on. They dampen the obnoxious noises and I can listen to something I find tasteful, like J-POP.