Build the box
First of all, you have to have a shoe box. Cut eight keys on the top of the box.Then, put some aluminium on every keys, on each faces. Then, makes holes for the cables and for the audio exit. Then, you have to create a false-floor, with solid cardboard. On the false-floor, you have to input the springs just below each keys.
Create the circuit
We have two principal circuits, one for the lights and one for the sound.
For the light, we start by linked the 3 bargraph with extensions, and we link all of this at the alimentation. We add an oscillator to control the lights intensity.
For the sound, we linked between each other three makeymakeys, who are link to an USB alimentation. Makeymakeys are connected to the computer and the alimentation.
Put together box and circuits !
First, you have to stare the light system to the false-floor. For this, you can use scotch. You have to make a hole, and put the oscillator in.
For the sound system, the circuit will be under the false-floor. The makeymakeys have to be connected to springs with crocodile clip.
The piano is ready!