So cool! My son had Legos for years - at the time he gave them up, the best Lego sets were trucks that you could actually move (Technic) sets. He recently got his daughter a Lego roller coaster set with an additional motorized part that runs the roller coaster. It is the neatest thing. They had a ball constructing it and she has it proudly displayed. The piano is really something too though - such imagination and ability to be able to design and produce such an amazing piano!