Missing files - iTunes using wrong path, how can I change it?

Question

Hi,
I store my itunes library on an external hard drive and I have over 1000 music files which itunes cannot locate even though they are there.
Having done a bit of research I've discovered that the path for these files is incorrect.
The path in "Get Info" for a missing track shows the path as:
file://localhost/Volumes/Public/My Music/iTunes/iTunes Media/Music/Artist/Album/Song.xxx
The path for a working track shows:
/Volumes/Public/My Music/iTunes/iTunes Media/Artist/Album/Song.xxx
So the missing ones have the extra "file://localhost" which I don't think should make a difference, but they also have an extra "Music" folder.
Is there a simple way to correct this for all the missing tracks?
Thanks!

Answer 1

https://discussions.apple.com/message/20401436 - turingtest2 11/2012 post on rebuilding empty/corrupt library from previous iTunes library file after upgrade/crash.  -- Possibly not what you want to do since your old library file may be very out of date.  You don't say if this happened because you were updating iTunes right now in which case this might be the best way.  If you recently did update you can take the archived library file and move it and rename it so it now becomes the library.itl file iTunes is using.
A slightly different approach to rebuilding, using a copy of the library file that is stored in a different format (.xml).  It is up to date as regards to your main library file though it does omit some of the things I mentioned in an earlier post.
iTunes: How to re-create your iTunes library and playlists - http://support.apple.com/kb/ht1451 I'm going to copy and paste, and edit the applicable section since it's a bit mixed in:
Re-creating the iTunes Library file
Note: After re-creating your library, any devices that you sync with iTunes  (Apple TV, iPod, iPhone, iPad) will see your iTunes library as a new  library and will completely resync. The next sync with such a device will take longer and may reset some options since your rebuilt library isn't familiar to the device.
1. Quit iTunes.
2. Locate your iTunes folder (this is the folder that contains the iTunes Library and iTunes Library.xml files).
/Users/[your username]/Music
3. Open your iTunes folder.
4. Drag the "iTunes Library.xml" or "iTunes Music Library.xml" file to the Desktop. If neither is available, learn how to add files back to the Library (because the XML file is not available, playlists and other information will not be available).
5. Drag the following file from your iTunes folder to another folder.  The file can later be trashed:
"iTunes Library" or "iTunes Library.itl"
6. Open iTunes.
Important: Do not add any content into iTunes at this point (such as by purchasing something from the iTunes Store).
7. Choose File > Library > Import Playlist.
8. Navigate to the "iTunes Library.xml" file on the Desktop.
Mac users: Click Choose.
If the above does not work we will need to edit the .xml file you are storing on the desktop  because it is derived from your .itl library file and it too may have the broken links in it.  It's the "file://localhost" stuff that's causing the problem.  The links aren't truly invalid, it's the fact that iTunes for some reason is inserting the localhost stuff that's causing iTunes to see them as broken links.  This can be edited  using a search and replace with a text editor, if necesssary.
For what it's worth, if you don't have too many broken links you could fix them by hand, but it's not fun.
Note, in addition to backing up your whole iTunes collection periodically, it is worth occasionally backing up the library file in case it becomes corrupt (as it is now in a way).