This prototype solves the Challenge: "Music to my ears" Create an object that makes sound or music, with the following parameters: "Permanent" and "Design for Them" This box has a basic [555 timer toy organ circuit] (https://electrosome.com/electronic-piano-555-timer/). The top piece an box are connected together with a spring so that as the cat moves across the box the top tilts one way and then the other triggering 2 tones. While this box is fixed permanently by the cat door and it is designed for cats to make sounds as they pass over it, it is really made for birds because it alerts them that the cats are now outside.