A problem with custom songs

So as mentioned a few days ago. I began working on a level editor. 

I recently discovered a problem and have been unable to fix it even after looking into it for days. I cannot load in mp3 files.

This is very inconvenient because mp3 is the dominating music format and not being able to use it makes it slightly harder to make custom maps for some people who don't know how to convert.

The main supported format is WAV. So people who want to make custom maps will need to use WAV files for the format, this shouldn't be a problem for most people because you can simply search online for a mp3 to WAV converter to convert your song to use it, although it is inconvenient.  (ogg files work too)

Either way, progress on the editor is being made daily, so make sure you follow this page or bookmark so you know when the update releases! Thanks :)