So first, Go to your SMBX folder, Go to data and locate the file named "Music"

Copy it, And paste it in your episode folder. Next, Get some music! I recommend using this site:
https://downloads.khinsider.com/
Download some tracks and go back to your episode folder. Remove this text in the music folder in your episode:

(You can do this with any file down to music-16) And replace it with your music file (Example: World 1.mp3, Mario map 4.ogg, etc) And make sure the file ex is there (.mp3, .ogg, etc) If the track you want is in a subfolder, do something like this: Custom music/world map music/World 7.mp3. Make sure to save it when done (Also try not using music-17, It does not work sometimes) If you have any other questions, ask them in a reply. I hoped this helped someone!
