I found the best solution when we had problems with very loud music at all hours was to out do them. I got all 3 of my huge guitar amps, placed them against the neighbours wall in our living room, turned them all up to max and played at all hours. Within days their loud music stopped and has not come back. I think sometimes people dont realise how loud music can sound next door in a semi or terraced house, and it just takes a little realisation to occur to get them to change their behaviour.