This time it was someone standing at the end of the carriage with their music turned up far too loud so that everyone else can hear the "boom-tish... boom-tish... boom-tish" of overpowered earphones. Someone wandered down and quietly asked them to turn their music down (so quietly that I couldn't hear what she said - protip: if your music is louder than someone's voice, then turn it down), at which point the person with the music exploded with "Just leave me alone! No-one else is complaining, the guard didn't complain and he was closer to me than you are, just leave me along!".
Bear in mind this is Britain, so a lack of complaints doesn't imply that nobody minds. There's a certain element of minding your own business when it comes to trains - witness the tube at rush hour, where despite being packed in like sardines no-one complains about the person next to them.
Anyway, she eventually gave up asking, and a few minutes later the guard turned up (I don't know how the guard got involved or why), at which point the guy with the music started accusing the guard of being racist.
Sigh. Because of course it's race that's the reason behind everything, not playing your music loudly or being annoying.
Oh dear, he's still here complaining to the guard about people complaining about his music and not showing respect and discriminating against him.