BrickUnderground

Our downstairs neighbor has written a pretty contentious/frustrated letter complaining out my kids' piano playing. We have a rug under the piano and limit their playing to two hours a day and adhering to the rules of the building in terms of the times that they play. Does he have to right to curtail the playing? Should the neighbor chock this up to apartment dwelling? The neighbor did suggest a sit down and drink in his apartment to discuss this and to also have the opportunity to hear how loud the playing is from our apartment. Lastly, to try to appease the neighbor-are there tricks to muffling the sound of the piano that people have tried? Thanks.