Arduino Piano - Pentotron

HI! This is my first instructable, ill do my very best to make it a good one. Im not a native speaker, so please keep any mistakes you might find.
This instructable will show you how to build your own arduino “piano”. It plays only pentatonic scales and therefore just has 5 keys. If you dont know what that means: Dont worry. Itll always sound nice and makes a great toy piano. You can change the key with a knob(so you can play in any key) and switch from major to minor pentatonic scales with the help of a switch. A lot of keys and switches here. Lets get going.
This is a rather easy project to do. Youll need:
1x Arduino Uno 5x Momentary Switches 2x Rocker Switches 1x 1/4 inch guitar jack (or a Piezo /8 ohms Speaker if you dont need an output jack) 1x Potentiometer 1x 9v Battery 1x 9v Battery Clip a soldering iron or a breadboard (and in that case some dupont wires) any sort of housing some wire”