Ok, there are also another cathegory of chips with which you can really play programmable scripts as tone of a variety of instruments, if I'm correct these ICs are comaptible with the MIDI, but they were not in fact used for toys, but rather with games and music instruments, but to be honest I do not remember the P/N of any one right now. The usage is more complex, you have to first play the music in some instrument, and then export the raw text result that would should be imported on the uC firmware, which would send it to the embedded IC, not a too simple process.