Chapter 29 told a short history of the Mason & Hamlin piano company, with stories of several Mason & Hamlin pianos that I have serviced over the years. I mentioned that world-class Mason & Hamlin pianos are being produced again at a factory in Haverill, Massachusetts. Here is a link to their website:
There are remarkably informed people offering seminars for members of the Piano Technicians Guild. One of the seminars I attended explained the difference in piano tone that results from differing piano soundboard and bridge designs. Mason & Hamlin pianos are valued for their resonance and long-lasting tone, whereas some other brands are valued for their sudden, bright, and loud tone. If the designer of a piano wants a loud sound and does not care if the sound sustains, then the appropriate design would use a narrow bridge and a thin soundboard. If the designer wants a long-lasting tone, then the design would require a slightly thicker soundboard and a wider bridge with more mass. Most often a designer would choose something in the middle to get the most possible of both qualities.
If you are not familiar with soundboard and bridge design, the bridge is the connection between the soundboard and the strings. If you have a grand piano, or have access to one, you can see the bridge at the far end of the strings, away from the keyboard. The strings are securely attached to the bridge, so they will not cause unwanted vibrations, and to make sure the vibration of the strings gets communicated to the soundboard, the large piece of wood which amplifies the sound.