For my character to be able to play guitar, i needed to do one of two things. Have two hands (left and right) which were bendable, and stuck in a specific shape. Or make around 10-12 individual hands which could be swapped over when neccessary. As the thinnest wire i had was copper, I went for the second option and started making 12 individual hands. This is how they were made.
In order for me to be able to swap these hands over quickly, without having to remould the wrist after each change i have made a tiny watch to cover the join. It is also partially covered up by the neck of the guitar.