Today I build Simon a new toy, a giant wooden xylophone. I read an instructables and thought I would make something similar with some scrap 2x4s.
I started with a 10 inch piece and got up to 28 inches before running out of wood. There is a 2 inch difference between each board.
I drilled through the boards with a long spade bit to run the rope through and tied a small knot between each one.