You may have thought that researchers had better things to do than to determine if it would be possible to create a metallophone instrument in which the keys to be struck had the shapes of animals, but, frankly that would just indicate a lack of imagination. A team from multiple universities has come together and is releasing a paper called "Computational Design of Metallophone Contact Sounds" in the journal of the Association for Computing Machinery, Transactions on Graphics in which they detail an algorithm they have developed for doing just this. The original shape combined with desired outputs in terms of pitch and volume were subjected to the algorithm in order to deform the model of the key to be created in such a way that the note would be on pitch and at a reasonable volume level. The final creation is called the Zoolophone and while it probably won't be in stores by Christmas, may eventually lead to people being able to 3D print their own note producing shapes. Read more at 3DPrint.com: http://3dprint.com/102906/3d-printed-metallophone/