I am going to do a small series of articles on piano regulation.  Many people do not understand what this is and therefore do not recognize the value of a regulated piano.  The first article will deal with key leveling.

The first thing a piano technician will most likely do in a piano regulation is level the keys.  They are made of wood and sit on small pieces of felt and paper called punchings.  They wear and warp over time so they need to be adjusted every so often.  As the keys go out of level, the entire geometry of the action mechanism goes out with it.  Not only does a level keyboard feel better to the pianist, but it also helps the piano perform better.  The black keys must be at the proper height above the white keys otherwise your fingers are thrown off with having to reach too high and stumbling or not having to reach high enough.

In my opinion there is not much else so beautiful as a perfectly level set of keys.  (Perhaps only a piano technician would say such a thing.)