You said your music lives on the external hard drive (/hd/users/username/music/itunes/music) and that's where you pointed to in iTunes 11 in Preferences > Advanced for iTunes media location, right?
But where does the iTunes Libary.itl file live?
Check your old ibook in user/Music/iTunes and see if it's there. If so, copy that .itl file to your new iMac in the same location and relaunch iTunes. iTunes should see that itl file and update it to the new version of iTunes. All of your playlists, ratings, etc. should come across.
What happens is iTunes looks in your default Music/iTunes folder for the iTunes database (itl) file. The location you specify in iTunes preferences is just the physical location of the media.
You can hold a key when launching iTunes (maybe control or Shift?) to get a dialog for specifying which itl file to open. But if you don't do that, it looks for the one in the default location.
You have to add the music to the new iTunes library before iTunes will recognize it.
1. Open iTunes.
2. Open the Prefs > Advanced; unselect the option to "copy files to iTunes Media folder..."
3. On the same panel click the Change button next to the iTunes Media folder location and set the appropriate folder as the default location for the library.
4. Click OK.
5. Pull down File > Add to Library; navigate to where the music is on the external HDD, highlight the folder and click Open. This will add the music to the library.
Thanks, that's the first really helpful thing I've heard. I looked on the iMac and the iTunes Library.itl file lives on the first layer inside the iTunes Media folder. When I looked at the mess that is my old iTunes on that first layer there is an iTunes Library.xml file and an iTunes Music Library.xml file but the only .itl file I can find anywhere is in a Previous iTunes Libraries folder and it is named iTunes Library 2013-01-14.itl. The date is, I assume, a prvious effort to move things. Is there any way to fix this?
OK. let's first make sure that it's the iTunes Library.itl file you had found that's opening on your new iMac.
Hold down the option key and relaunch it.
In the Choose iTunes Libary window, click Choose Library and navigate to that itl file you had located on the iMac.
If that doesn't fix it, then copy that older dated itl file from your old ibook to the same location as the other itl file on your iMac and repeat the previous steps. Except this time, select the one with the date.
Thank you Michael, so far so good; but, is there anyway to get the playlists? It seems to have added the music to the library while leaving all the files in their original place on the external hd and it seems to have found all the available music and works when I closed and reopened iTunes but there are no playlists. I hate having to rebuild playlists even though i should this time at least be able to just move the HD over to the iBook and get the contents from there if I miss any.
There are a couple of ways you can proceed. Do as GregMac suggests and find the .itl file from the book and drag it over to the new Mac. O, you can export the playlists in iTunes on the iBook, then import them into iTunes on the new Mac.
Regardless of how you proceed you need to be doing regular backups of your personal data.
Thanks, Michael, I will try the export/import route. I do backup everything automatically from the iMac. Oddly enough, I thought having my music on an external would make it easier to be both portable and backed up but iTunes is just persnickity. I am a bit worried about the .itl file since there is only one and it is in an old library. It makes me wonder why it would be only there.