There's a lot going on behind the scenes that isn't readily apparent from listening to a song. Though sometimes, a simple investigation of writing credits can tell you a lot.

"Ghostwriting" by its proper definition refers to contributions from rappers who have not been credited-- which is a pretty grey area. Rather than look into rumors surrounding that type of writing (with one exception), we've looked into what's available in print, but may have gone relatively unnoticed-- official songwriting credits.

While we may never have the full story on many of these songs, the liner notes definitely give a better insight into how they were created.

Flip through the gallery above, and let us know which surprised you the most.