Hello everyone,
Today I went to the piano shop and just scoped around the beautiful pianos that were around me. Then I noticed something that doesn't come up much into topic, and I couldn't get it out of my mind and now I'm really itching to ask

. Why are the case (the legs, exterior frame, etc.) of most pianos still primarily made of wood? Well the obvious answer may be because for the acoustic, but isn't the majority of the sound amplified inside the soundboard and the frame? The legs and the exterior is chosen primarily for sturdiness, right?
Well, that brings me to ask, why chose wood? I see alot of pianos that have metallic exterior or even glass (which Lady Gaga plays sometimes in her concerts), but I don't generally see them available to the public. A vast majority to this day are still made of wood. Is there a special part wood plays in for the exterior design of a piano? I know it is mandatory in most pianos for the inside of a piano because of its qualities, but wouldn't it better if the outside was made of some metal or even glass?
It might be cool if pianos were made of recycled metal and cheaper than wooden parts, plus that means we need to worry about humidity less.
I'm not an expert in pianos very much and any insights/comments or answer to my burning question would be greatly appreciated!!