Here's a draft of the MP3 player.
Currently the broken folder skip buttons (folder skip wasn't co-operating with me) is set to jump the tracks ahead by 5 or so, sometimes more if you've pressed "skip track" a few times.
Add to the coding with the arrows to expand how many songs you can skip. I haven't written anything to re-set the counter to zero once you'd skipped all the way to the end. But with 100 albums worth it think that'll take a while.
i'll let you know if i make it bluetooth compatible but i see a straight bluetooth module that connects with almost no effort at all...