We all can't be perfect, some us have to be mainehccals! (Actually my degrees are in ME and AE).Your music solution would depend on the fidelity of the music. Do you need a piano, oboe, sax, tuba, or would a pure tone note be adequate?If a pure tone is adequate, you can likely make due with a simple micro controller like the PIC, MSP430, or a dozen other small devices. If you need a real sounding instrument, then you have two choices. A device that records and plays back a tone, or a synthesizer.Your problem space is pretty large. You also need to define battery requirements such as type, number, and duration. You also need to know the fidelity as mentioned above and your unit price cost.