I have a huge old MP3 collection which I recently copied onto my mac.
I then opened iTunes and it quickly did a scan and added the files.
I then removed all the files from the iTunes library and added them again.
It then took about 30 minutes to 'process' the files and this music dir is now twice as big. It seems it placed all the files into its own media folder.
What is the difference between these files in its media folder and my original files?