The Piano is surrounded by an mysterious fog of misinformation and erroneous belief.
This information is devoted to dispelling the more prevalent misconceptions.
Probably the most damning thing that the layman can say about a piano is that it has a cracked sounding board. Horrors! It's ruined beyond reclaim!
Now, the interesting thing about these horrible sounding board cracks is that on one, - but on one, can tell you just what this crack does. Where-in is the piano injured? These questions remain unanswered. "But the piano is ruined. I heard my sister say the family Mason & Hamlin grand piano with several cracks in the soundboard claimed it was the best piano she has played on, but yet it was ruined because of the cracks."
A peculiar characteristic of this theory is that , no musician, teacher, piano tuner, salesman, piano designer or anyone else will wager that he can play on a strange piano and determine without looking where a sounding board is cracked and if so how much. A blind piano tuner doesn't know a sounding board is cracked unless someone tells him. It matters not, as long as the soundboard has crown, it could have one or five cracks, as long the the ribs are tied together with the soundboard, and the soundboard must have crown. The crown allows the board to sing, without crown at best the pianos will sound and no longer have the ability to truly sing.
A sounding board is a huge diaphragm that amplifies the vibration of the strings. It acts and performs as a unit. Tone does not ripple across like rings on a lake disturbed by a stone tossed into it. A crack is a little consequence because all the individual boards glued together to make up a sounding board are tied together by the ribs. It will excite as much air, cracked or not.
The only thing that might happen is that after 30 to 40 years the sounding board can become loose from the ribs. In this case it will rattle with one of a series or even all notes. A competent piano rebuilder can glue the board back down on the ribs and end this trouble permanently at a small cost. Or, at great expense, he can drive a wedge shaped piece of wood called a shim down into the crack with glue and the crack can't be seen. Knowledgeable rebuilders have never felt that this was justified, except that it makes a prospective buyer happy if the sounding board isn't cracked. As long as the sounding board is tightly attached to the ribs and has a nice crown, crack or no crack seems to make no difference at all with some of the finest musicians.