Inside an upright piano
An upright piano divides into three main parts
The harp starts with the the soundboard, ribs and bridge. This part is often discussed as the ‘soudboard’.
Ribs - Sound travels down the grain of the soundboard, by adding ribs, the boards connect to each other and the sound travels up and down the ribs to each corner of the piano.
Bridge - is the point of contact between the soundboard and te string, vibrations from the string pass onto the bridge. As vibrations travel up and down the bridge, they are transferred to neighboring strings. And collectively the bridge vibrates through the bridge onto the soundboard.
Frame - The iron frame creates the stability of a piano. The amount of pressure bearing down on the bridge would be too great unless the frame suspended the strings slightly above the bridge. In addition older wooden frames would crack, rendering older pianos useless. Less common in the US, however, more common in Europe.
The Action and keyboard
Keyboard - Is the basis for the touch of a piano. The amount of depth the key can down down, and the original height. All these effect the gradients in touch. And the weights in the key determine the up and down weight. Very important for the feel of the keyboard.
Action - the action will have its own article. The action transfers the players energy to the hammers. A well adjusted action is set-up to play evenly, with a slight gradient from top to bottom. Slightly lighter in the top, slightly heavier in the bass section. Other elements of the action enable quick repeated playing (repetition), ppp to fff playing, etc.
Dampers - stop the strings from vibrating so that focused playing is possible.
The cabinet traditionally (as with most areas), requires a team of carpenters. They devise a style that is both relevant in people’s homes, as well as accesible for the piano tuner. Some cabinets such as the scissor falboard are less easy to remove for repairs, than others that just slip off.
As a tuner/technician myself, I am always fascinated by the construction of pianos. And taking one apart to explain teaches me as much as you may have learnt. Interestingly, you can always learn something new with each day working on the fine instruments. I hope this article was informative. If you believe there to be innacuracies, or would like to make a comment. Please email email@example.com. Thank you for your time, Evan Roberts