how do you get a neighbor to stop cranking up the music?

It sounds like you are doing all the right things... reporting it to the police and the appt manager.. other than that you could try talking to the neighbour and/or writing them a note about how much it affects you? 

Ear plugs. It sounds like you live in a noisy apartment. You've had to deal with construction, neighbors who talk too loud, and now loud music. At this point, it may make more sense to control what you can and either get earplugs or play some ambient noise to drown out the other sounds. 

I have never had an apartment without noisy neighbors. We had one who liked to play drum late at night. Don't know who it was for sure as we had 4 apartments above. And the one directly above had teens in it who got home late. They weren't loud music wise or other but it sounded like a herd of elephants going up the stairs....that was our joke. "The elephants are home."
We did hit the ceiling as few times when they got loud....did not help. But if they had gotten too loud we would have called the police. Which is what I would recommend for you to keep doing.

Be thankful that you have contented neighbors.

I just cranked up my Spice Girls CD's louder than whatever he was playing. 

Record it, then play it back at distortion levels the next morning when he's trying to sleep off his hangover.

In addition to calling the cops and the apartment manager ... EVERY time ... IF your apartment has a 24/7 maintenance line, call that at 3am in the morning (or whenever it happens).  Also, get you other neighbors to call with complaints.