I also have some blogs about how to set up your own internet radio station at the above link.
I use Solar Garden lights to power this project, but for this instructable, I'm showing the basic concept of the construction. How you power it is up to you.
Step 1: Make the support
I used 1/2 inch steel angles at the ends to support the wires with screw eye bolts. 24 gauge solid steel wire from the hardware store is used for the strings. You can try different thickness for different sounds. Just remember they must be steel or iron, the strings vibrations must interact with the magnetic field produced by the pickup coils, just like a electric guitar.