figure out how these actually differ and such.

• should the various electromechanical pianoes be subtypes of a generic "electromechanical piano" which is then a type of "electric piano" ?
• or is that all electric pianos are electromechanical, while the purely electronic ones are synths?
• reo, what is a "digital" piano?
• how does keyboards(our instrument) fit into this?
• at what point does it go from "string" to "electronic" instrument? percussion?
• ???