Hammer shaping is a job that very seldom gets done. Yet Hammer Shaping is one of the most important jobs of piano regulation. Whether we regulate or not hammer shaping should be done occasionally. Especially if the piano owner wants their piano to sound like a piano. Hammers can move from side to side and get out of line with the strings. If a hammer gets out of line with the strings and the edge of the hammer is hitting the string with a glancing blow it will cause that note to sound harsh. If the hammers have deep grooves in them they will muffle the strings and when you play a note it will sound muffled because the strings have become encased by the rest of the hammer. If the hammer has deep grooves it also means that the hammer has worn flat. It no longer bounces off the strings the way it should. Shaping hammers is a job we like doing because you can hear so much difference in the sound. When the hammers are shaped the piano can be regulated, (and it should). It becomes possible to set let-off, blow distance, drop, and many other points of regulation which make the piano play smoothly. At this point the player gains control of the piano. The player never has control of the instrument until the piano is in regulation and every note plays the same.