RE: Ultralight acoustic piano - Sorry to disappoint you, but the majority
of the weight in an acoustic piano does not come from the "furniture"
aspect. It is due to the heavy cast iron plate and corresponding structual
assembly required to support the combined string tension of approximately
20 tons of tension! Although modern metalurgy can produce an appropriate
structure, it is presently way out of line from a financial standpoint.
Although I rebuild, tune and prefer to play acoustic pianos, and use the
next best SUBSTITUTE, the electronic keyboard when I need portability.
Note: before you electronic fans start screaming replys to this, keep in
mind that there is NO electronic keyboard that can do what an acoustic
piano can do. They can digitize it, synthesize it, ALMOST sound like an
acoustic piano, but when being played, I have not found ANY electronic
piano that can reproduce the effect that can be gotten from an acoustic
piano, i.e. sound waves blending, amplifying each other, canceling each
other, etc. which can only be gotten from a vibrating membrane such as an
acoustic soundboard.
Well, I did find this... It's a new-built square piano. https://www.jc-neupert.de/en/component/virtuemart/neue-instrumente/tafelklaviere/square-piano-mahr-detail