I've moved iTunes to an external hard drive now have massive duplication of albums

Question

Recently moved my iTunes folder to an external hard drive. Used the Itunes preferences to transfer the itunes folder to a new location. Didn't transfer it manually or by drag and drop! Followed this - I hope correctly - by using the iTunes/File/Library/Organise Library tool. May have got this bit wrong....
Result?.........
Here we see, in the second column, that I have both an 'iTunes Music' folder and a folder simply called 'Music' (Highlighted in red). You'll have to take my word for it but these folders have different amounts of music in them. Some is duplicated, some albums are split across the two folders. Howwever, most empty folders are in the 'iTunes Music' folder, whereasost complete folders are in the 'Music' folder! In addition, There's a 'Compilations' folder within the 'iTunes Music' folder (highlighted in blue with a red arrow) which has a small number of compilations most of which I've never selected as compilations.
Note the repetition of folders called 'Automatically add to iTunes' in both the 'iTunes' folder and the 'iTunes Music' folder. There's another one of these in the 'iTunes Media' folder.
Going further in.....
Here we have the 'Music' folder in the 'iTunes' folder. It has its own 'Compilations' folder which is even larger and more irrelevent than the previous one. It also has way more album folders than the 'iTunes Music' folder itself.
If I use the  iTunes/File/Library/Organise Library procedure the splash screen that comes up allows me to choose the first optiuon but the second one is greyed out.
One of the results of this is duplicated albums on my iPhone, another is randomly missing tracks in my collection. In addition, my iTunes screen saver now has duplicate album covers and many album covers that I know I've downloaded at high resolution have just gone missing making my iPhone look like its been populated by a chimp! (no offence to our cousins) Where I've discovered a missing track I've used the 'File/ Add to library' procedure. In one case it copied an album folder from the 'iTunes Music' folder where I found it into the 'Music' folder on another occasion exactly the same procedure left the album precisely where it was.
BTW, I have another iTunes folder on my Mac with all the normal stuff in it but only music that I had to add whilst nopt connected to my hard drive.
How can I remove this massive duplication safely?
How can I consolidate my files efficiently without having to go through each folder separately?
How can I remove all these albums from 'Compilations' and prtevent other albums being added?
How can I get all my album artwork back in sync?
Phew!
Thanks!

Answer 1

The folders and files are all normal to a basic iTunes library. They would be there even if you didn't have a single media file.  Until you start up with the option key held down, iTunes will keep on looking for your library on the internal drive and will repopulate that folder with those basics if you delete them.  You should have a similar folder with contents on your external and that is the one you want iTunes to use.  As long as you keep it all intact while copying from one drive to the other, iTunes will be internally consistent and you won't even have to change preferences.
Preferences window
iTunes Media folder location: Just that; where iTunes keeps media. This is not necessarily where the library files (which are what ties the whole thing together) are to be found.
Keep Media Folder Organized - put all your files in folders according to type and name and album etc.
Copy Files to iTunes Media Folder - put it this way, if you didn't have that checked itunes would leave the files wherever you had them when you added them to the library. this one makes sure there is a copy (though not necessarily the only one, but the only on iTunes uses) in your media folder.
What actions take place when itunes "consolidate library" is used?
When you consolidate iTunes looks at all the files you have listed in iTunes and puts them in the location indicated by your media file preference.  I don't think it hunts around your drive looking for things that aren't in the library, it just places a copy of those that are innto your media folders.  If you want a searching tool you'll have to use a script that does that kind of job.
Your original images are not showing for me so I can't tell what exactly you are seeing.
Again, what I would do given what you have told me is I would make sure iTunes is using the library on the external by holding down the option key while starting iTunes (you only neeed to do that once).  If you find there are files on your internal drive that are not in the library on the external then add those and iTunes will place a copy on hte external if you have that "copy files..." preference checked.  You'll lose a few things such as playcounts, ratings, on those.  If you absolutely must keep those there are a few tricks that can be performed but that's another very long post.