There are two kinds of people in this world: those who use earbuds, and those who play their music out loud for all to hear. If you're going by anecdotal evidence (ie. people complaining on social media), loud music in public spaces has become a big problem. It does seem to be everywhere these days: people will enter a subway station or plop down in the middle of a crowded park and start playing music at top volume. It doesn't matter to them that lots of other people have their own music playin…