Broken Plate! Who is Responsible?
The Plate is the cast iron frame of the piano (some people call it the "harp"). A broken plate is extrememly rare but catesrophic for the piano. This article discusses this issue and has a link to a reprint of a whole Piano Technicians Journal issue about the piano plate.
Video
How it's made - The Piano
This is a YouTube video from the Science Channel that shows how a Mason & Hamlin piano is built.
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