Hi 27 steps,
Firstly on reading your comments that you are a bit scared.....dont be. You have rights.
I would take another neighbour or two with you and call round to politely share your views with him that his loud music is causing you misery. He may be understanding and comply to your request and apologise.
Thats the first port of action. Second one is too go to his Landlord, as Redcrx so rightly says....see what he or she will do about it, as they are most certainly totally unaware that their noise is causing you grief.
Thirdly, if still no joy, go to your local council advice or citizens advice centre for more guidance as what to do and call the police anonomously if really bad at day or night.
and lastly, I would call the noise abatement society and ask them to visit when it's loud...they will advise you of what they will do.
In answer to your second question, the vast majority probably dont give a stuff about other people in flats, houses etc.....and that is why it must be sorted out..........
I do really hope you get it all worked out, 27-steps....and best of luck to you.
Keep us aprised if you can, and if you wish too.
Kind Regards
yogi