A piano keyboard is not too hard to make. It's based on the simple box mechanism. As is usual in origamic architecture designs, cut lines run vertically and fold lines run horizontally.
I made this as a thank you card. The striped paper was cut to fit around the keyboard.
The design is not mine. There are any number of variations around the web. I did draw my own template, however.
Red lines=valley fold. Green lines=mountain fold. Blue lines=cut.
Too complicated? For an easier design with less cutting, try this design instead.
I borrowed much of my design from Marivi Garrido.
Here are some other variations on the theme.
From Unique Projects
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.