Sound Proofing

[Sciolist]

A friend of mine just bought a flat, but quickly discovered that the guy living above him plays loud music all the time. I don't think there's really a legal recourse: He can get into a battle about environmental sound standards or whatever, but it'll take months and the guy upstairs is (allegedly) a drug dealer.

Is there anything you can do with sound proofing to stop this kind of problem? Can you lag the ceiling or something? I don't know what you can do to stop bass, I gather it's the hardest thing to keep out.