In my opinion, we all have our own lives and we are definitely upset when others shadow our lives. How can we properly avoid this kind of problem? Here is my experience, I hope it can help you a little.
I am a guitar enthusiast and have been learning the guitar for many years. Of course during this time, it certainly affects those around me while practicing. There's nothing wrong with playing the guitar, it's just that it's the wrong time to be practicing. I made an agreement with my neighbors that I would only practice during the day or go out to the rehearsal room, and I would never disturb other people at night. So when people are in this situation, where other people's music or other sounds are affecting them, it is more reasonable for us to negotiate with the other person and adjust ourselves. Strive to not affect yourself when the other person is practicing the piano. This will not affect others, nor will they feel helpless, and perhaps enhance the feelings between neighbors.
Of course, this does not exclude some of the more extreme cases, if you upstairs neighbors in your discouragement still do not listen. This time also can not be resolved through violence, we can consult the community council or property, let them to manage this problem. It is of course the best if you can solve the problem peacefully, but if you can't, you can only ask these departments to manage the matter. Anyway, when we encounter this kind of situation, the most important thing we should do is to keep our sanity first and use the right way to solve this problem. If this is not possible again, then we can only bring out the judiciary to handle this kind of thing.
Music is wonderful, but when it appears at an inappropriate time in a place where it should not appear, then the sound becomes noise. Just like the square dancing amazons, it is good to get fit, but disturbing the public is their fault. So that we have to come up with a reasonable way to solve the problem.