If a zombie had a piano, this would be it.
You could also try to make a guitar instead of piano keys, just be creative :)
Draw the piano keys on the piece of paper using a pencil ( you can get an image on google if you're not sure about the black keys. I used this http://store.drumbum.com/media/piano-keys-decal.jpg). Overline it using a black pen.
Glue it to the cardboard. Any kind of glue will do, I used regular white glue.
Paint the keys that are supposed to be black using the sharpie, wait for it to dry and cover it with a layer of glue.
When it's dryed out, cut the carboard and the paper to the shape of the ring.(You can make round corners like I did, or just leave them the way they are.)
Glue the ring bases together and then attach it to the back of the cardboard, being careful to place it on the right position.
This step is optional:
You can use yellow, purple, green and pale pink markers to give it a kind of "dead" thing to your ring, you know? I think it adds up a nice touch of rusty.
Just paint over the white keys( that are covered in dry glue, so the paint shouldn't stick too much) and smudge it with your fingers.
You are done!!!
Have fun making your own old piano ring :)