Know that this will cause i Tunes to lose track of where all of these files are; meaning you will have to re-add them to the library (manually), which will take you hours and which may mean you will lose play counts and any other information that i Tunes keeps in its own library.
This method is a bit more complicated to set up, but easy to use.
If you’ve used i Tunes on your new computer, move your media to a new folder. Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement.
Thanks to this, you can get a very large external hard drive at affordable prices.
This is another simple option to move your i Tunes library to a new computer, especially if the library is larger than the storage capacity of your i Pod.
When I add new music to my library I copy the music to my disk station Music share and in i Tunes I click, file, add to library and it automagically opens up my disk station Music share, from there I select the folder I want to add and I'm good to go, I do not know if this will help you, but this is what I did with my music library.
-Have you Run Disk Utility and done Disk First Aid and Disk Permissions repair (you might have to start off another volume to do the repair justice).-How big is your music Library?