One approach would be to write a script that went into the /music/Springsteen directory, grabbed all the folder names into an array, and then write a foreach that went into the directories one by one and prepended the directory name to the song's filename.

You could also write a regex that would search the song names for the directory name to avoid changing filenames that were already correct.

Sorry I can't write any example code right now, it's almost 5:00 AM here and I think any attempt I would make would be more amusing than helpful right now. ;-)