Has anyone ever made a music box? If so, tell me how.

I'm curious if anyone here has made a music box before. Recently, I made a custom box for the subwoofer for my car, and it was easy and pretty fun. Then I thought to myself, I want to make something else doing woodwork. I ended up deciding for a music box. I'd probably end up giving it to my girlfriend.

Anyway, I've found some plans on making mechanical ones, but I've heard they sell chips for music boxes now. I'm pretty sure it's not possible, but it'd be cool if I could choose what music to put in the music box I plan to make.

If anyone has ever done this type of woodwork before, I'd really appreciate any advice you can give me.