I created these CD shelves a number of years ago as a gift for my father. He still has them.
This was a very enjoyable woodworking project, as it involved building the shelves and then sculpting them. The wood used was pine, which is a softwood, which made it fairly easy to work with.
I drew out a design for the two shelves which allowed building them separately and then stacking them by means of four dowels which fit into holes in the top of one shelf and the bottom of the other shelf. Each shelf also has hanging holed drilled into the back, to allow mounting the shelf flush onto a wall.
I think of this as a functional sculpture, which to me is the best kind of sculpture, and the most enjoyable to create.