partial iTunes library gone

I just backed up my iPhone 2 days ago and am now going through my library and noticed that some files are missing. I went into my iTunes folder and see all of my folders from I - Z are now GONE.



What could've happened for this to occur, as I have not deleted or even touched my iTunes folder in MONTHS??!!

via ehMac.ca http://ift.tt/1A9mLDN