Anything between 1 MΩ - 4.7 MΩ is usable.
You will require a resistor for each note you plan on having I have 7 notes and 3 optional keys that allow you to change the instrument, but you could have anywhere between 1 - 11 notes when using an Arduino Uno, If you have another model you can create as many notes as the digital pins will allow!
- Copper Tape / Wires
- Conductive Thread
Or anything conductive that is in a similar shape that you will be able to wrap the thread around
- Soldering Iron + Solder
(These are materials I used to create how the instrument looks, but not necessary for the outcome of the technical side working)
- Hot glue gun
- Form Core Board
- X-acto Knife
- Masking Tape (very useful when soldering and putting together the circuit with copper tape)
- Different coloured threads