Put up a studded wall, probably with 2x4's on 16" centers. If you set them a couple inches away from the cinder block, you can use the 6" insulation. Look for the insulation that is for soundproofing purposes. Next you can put up a double layer of drywall and finish, you shouldn't hear a thing then.
Of course the other option is to make so much noise that your neighbor does all the work.