Don't put data file in executable folder. It is a bad pratice.
A file like a MP3 should be under user folder (and preferably in "My music".
By the way, your Path is wrong for sure...
1) "MusicFile" would never be at the beginning (before the current directory)
2) You should normally not use CurrentDirectory as it might be anything depending on how the application was started (from debugger, stanalone, from a shortcut...)
3) As mentionned above, you should use a folder specific to the current user.
4) You should use
GetFolderPath[
^] to get the desired parent folder.
5) You should then use
Path.Combine[
^] to build the complete filename.