I don't know if this is the only problem, but...
In JavaScript (and Java/C/C++/C#/other languages) the backslash character is used as an
ESCAPE character, giving special meaning to the character it. The \n means "newline" and \t means "tab", etc.
If the following character does not have a special meaning then then the character, alone, is the result. The backslash just disappears.
In order to actually *GET* a backslash, then, you must use a pair of them.
Code:
'C:\Users\Willium\Music\Area Cleared.wav'
became just
'C:UsersWilliumMusicArea Cleared.wav'
so you needed
'C:\\Users\\Willium\\Music\\Area Cleared.wav'