I made four of these music boxes as christmas gifts to my family. The PDF pattern was generated with a Processing script, which I wrote. I've included the script for reference, although you only need the PDF to produce copies of the box. Each box is laser cut from a single piece of 12x12 plywood.
Here's a video of my daughter on Christmas: http://youtu.be/n9I88Lt0zUw
The lid of the box contains an inlaid Hilbert curve, a kind of space-filling fractal. A more detailed Hilbert curve is etched into the bottom of the box. The sides of the box contain inlays or holes in the shape of the letter J, which is the first initial of each of my four family members.
The pieces of the box fit together like a puzzle. Each side contains a single letter J, which I dyed different colors, using food coloring. These could also have been left as holes, to make the box louder.
The crank hole is designed for a very common type of hand-cranked movement, of which Kikkerland is one manufacturer.
The pattern is designed for 12 x 12 x 1/4 inch wood. I used pine plywood from a local hobby shop. If you use thinner plywood, you'll need to tweak the puzzles edges of the pattern for the thinner wood.
Load the pattern into Corel draw, or whatever you use to print to your laser cutter. You will need to change all the lines to hairlines to make them cut. Everything in the pattern is a line, except the red area, which is etched, so it's safe to do a "select all" and then select hairline thickness.
If you are using a different music box movement, or no movement, you should adjust or remove the side hole that is intended for the knob/key. You can replace the J letters with a different letter, or design of your choice. The Js I used come from the Zapf Chancery font.
The pattern is 10.5 x 10.75, filling most of a 12x12 piece of wood. If you are cutting two boxes on a 12 x 24 piece of wood, I suggest cutting the wood in half first, to ease warping. This will improve the accuracy of the laser.
After cutting the pieces, I carefully removed the inlay piece from the top, and the J hole shapes, and set them aside. All the remaining pieces (the top frame, the sides, and the bottom) I sanded and dyed with a cherry wood stain.
The inlay piece is very fragile and should be handled (and sanded) carefully - it is a single curve, whose two halves, and 4 quadrants are connected with a single piece (like the brain's corpus callosum). Those connective pieces can receive a lot of stress, and fracture if you aren't careful. For my box, I left the inlay piece it's natural color, to contrast with the darker stain. I glued it in offset by a few millimeters, which gives the edges of the Hilbert curve a nice shadow.
I dyed each of the J holes a different light color (yellow, red, green, purple) by submerging in a food coloring / water solution for a minute. You could also leave the J holes out (which will make the music louder), or put them inside the box as charms.
I cut adhesive felt pieces for the interior of the bottom and sides, leaving a square hole for the music box movement. The music box movement can be screwed down or hot glued in (I used small screws).