Alright, so I fixed the music, and though my solution seems ridiculous, it worked (for whatever reason). I did these steps one by one, so I'm pretty sure I isolated the issue, but I'll give all the steps just in case someone else can make heads or tails of it.
First I renamed all of my mp3's and my iso file to match that of Dejunai's. I thought perhaps (like mame) Picodrive only searches for mp3s based on specific titles. (In retrospect, I don't think this is the case, because it had no trouble loading my iso, despite the fact that it too had a strange name scheme). I loaded this up, and there was still no sound.
I checked the files again, and coincidentally, I noticed that the .cue file in my folder was named ".CUE" rather than ".cue". I'm rather nitpicky about stuff like that, for some reason extensions in caps-lock bug me, so I renamed it quickly and then I was going to give up. However, when I loaded up the emulator, I noticed that now that I had renamed my .cue file (so that the extension was no long in caps) the emulator did NOT list it along with the iso. I found this strange since it always had before. This gave me an idea. I realized that perhaps the emulator didn't recognize the file as an actual .cue file because it was in caps.
I posited that if it didn't recognize a cue file (because of the caps), perhaps it didn't recognize my MP3 files for the same reason. So, I went through and renamed my mp3s from ".MP3" to ".mp3" and voila! The game runs the music perfectly.
The reason I say maybe someone else can make heads or tails of it is because, I figured that when it came to extensions, programs weren't case-sensitive. In other words, I didn't think it mattered if they were in all caps, some caps, or no caps. But the proof is in the pudding. My mp3s now play. Is this really what fixed the issue, or was it something else? Anyone care to shed any light on this for me?
FOR ANYONE ELSE WITH THIS ISSUE: Here is a very simple fix. I created a batch file for DOS that will allow you rename all your mp3's by simply following these short few steps. It's very simple:
First, create a new folder in the root of your C:\ drive called "TEMP". The folder's path should be "C:\TEMP\". Now, drag all of your MP3s (all at once, not individually by game. I promise they won't get mixed up) into the TEMP folder.
Then open Notepad and copy and paste the following text (everything within the brackets, but NOT THE BRACKETS! THOSE ARE THERE TO TELL YOU WHERE TO START THE COPYING AND PASTING):
[
pause
CD C:\TEMP
rename *.MP3 *.zip
pause
rename *.zip *.mp3
pause
]
Okay, once you have everything from the first "pause" to the third "pause" copied into your Notepad, save that file anywhere you'll find it. Your desktop is usually the easiest, and name it whatever you want. After you have saved it, close it. Now, rename the file extension from ".txt" to ".bat".
Now all you have to do is click on the .bat file. DOS will open for you. Press any key once it is open and it will rename your mp3s to zips. Then press any button again and it will rename your zips back to mp3, but they will all be lower-case. Now press any key to exit.
Now simply put them back into their appropriate folder, and PicoDrive will recognize the mp3's no problem!
Hope this helps guys. And thanks to Dejunai for leading me down the right path.
