I grew up on Lego. I loved it. With this one toy you could build lego equivalents of all those toys your parents wouldn't buy you. But for some reason I never asked my parents for a harpsichord.
Yes it is a working harpsichord build entirely out of lego bricks and the relevant pieces of wire. That boggles my mind. Especially since harpsichords pluck the strings instead of hitting them with hammers.
I'm guessing it doesn't produce concert quality sound, though. I wouldn't think that thousands of little plastic blocks would be able to vibrate properly for good tone. I know all my lego stuff got awfully creaky once they started getting large.