I'm thinking about trying out itunes match so that I can listen to my itunes library at work; however, before I subscribe I'm assuming that I should copy my itunes library to an external drive just in case iTM screws up my library somehow. I have an external HD that I use for Time Machine backups connected to my MB, so I was thinking about just copying my itunes library to that. Is it as easy as just copying the Music folder located under my username? That's where my library is located. If I copy my library to the external drive and iTM somehow screws up my library (changes album artwork that I have, replaces explicit versions of songs with clean versions, etc.), can I just copy over the Music folder from the external drive and replace the one on my computer?