This instructable, will be entered in the Art of Sound, and Pocket- Sized contests.
I made this a few months ago, so i don't have any pics of making it yet but i will soon.

Step 1: Supplies

You will need:
1 Headphone cord
2 Small speakers
1 Beef jerky chew tin (plastic)

Tools:
A hot glue gun
An X-Acto knife/Scissors/Drill
Shrink Tubing
Soldering iron
Solder
Flux
A hair dryer

Step 2: Preparing

Cut/drill two holes in the tin.
Cut the speakers off of the cord (If it still has them).

Step 3: Soldering

Solder the two speakers to the cord, then shrink tube them.
This step is important, because the original speakers on headphones are too quiet.

Step 4: Assembly

Use your hot glue gun to glue the speakers over the holes.
Then glue a portion of the cord into the bottom.

Step 5: Done!

You are now ready to use it.
I accidentally used the wrong speakers so mine is quiet.
In the video you can hear it while i try to solve my Dad's Rubik's Pyramid.
Here is the video:
http://www.youtube.com/v/vwo5G3u23E8&hl=en&fs=1
The song is - July by Dan Dixon
You can download it Here:

http://dandixon.us/music/