this tutorial will help people who wants to change the default music for both ygopro: launcher and percy.

first pick any 5 songs, or less if you want to hear one song over and over again, copy those 5 songs.
head over to your ygopro folder, inside there is a "sound" folder, open it up and paste the 5 songs into the folder.
next you want to change the names, or delete, the following: song, song-advantage, song-disadvantage, menu, and deck.
then pick which ever song you want to play when and name it.
song: when you first start a duel or you and your opponent's LP are close to each other
song-advantage: when you're winning
song-disadvantage: when your losing
menu: when you're waiting for a duel, or in the menu screen
deck: when your in the deck construction screen

that is the basic tutorial if anybody wants me to make a video of it just let me know and i'll update this tutorial, or if you want pictures i can do that as well, either way enjoy