I have some basic/hobby experience with electronics prototyping.
The second gift I made for my girlfriend. Made with an ATMega 328P-PU that plays two songs thru a piezoelectric speaker. Songs were manually encoded (played the notes frequency using PWM). I can only fit two songs due to the chip's limited memory.
The first gift I made for my girlfriend. I used an ATMega 328P-PU from an Arduino Uno board. The housing was built using a plastic food storage.