Migrating the iTunes library (non-default location)

[Riku7]

A search seems to mostly bring up guides on how to move the iTunes library with migration assistant or otherwise restore it into a default location, but since I don't store things in the default location, it turned out to be a bit harder to find resolutions.
Over the years, I have done so much work with playlists and all kinds of library sorting that I'm absolutely terrified of testing stuff out without knowledge of how to do this correctly, it'd be a disaster if my library metadata got overwritten or trashed somehow. The music files are obviously safe, but it's not enough.

My old Mac broke, and I cloned the old operating system inclusive hard drive to my new Mac. On the old computer, iTunes music files were stored on an external USB hard disk. Sometimes when iTunes would lose the path to the files (had I launched iTunes before connecting the USB disk), it would find it again when simply given the folder path in the format "USBdisk/iTunes".
In order to get rid of that unpractical USB disk business, on the new computer I'll want to keep the music files on an internal disk. But to keep the operating system disk as spacious as possible, I still won't want the music to go to the default location "User>Music" etc., but on another internal HD that I got solely for file storage purposes.
I moved in my old iTunes folder from the USB disk as is, but now if I launch iTunes with alt pressed down in order to specify the library just as I had done before, the path in the format "newinternalHD/iTunes" is invalid and it won't accept it.
The paths are so similar in nature, why isn't it working as before and what am I doing wrong? What's the actually important file called (and where is it), that truly stores the playlist, rating etc. information? Because up until now, the only path I ever gave iTunes regarding library location was USBdisk/iTunes, just like that.

A less important but related additional issue: Because iTunes sometimes dropped the custom library location, I have noticed that it sometimes accidentally saved a few music files into User/Music/iTunes. Playlists and all other such information is obviously constructed by using both, this default location oddball files as well as the ones in the external disk iTunes directory that I meant to be the real one. Is there a way to migrate the odd ones into the main location without losing them from the library and the playlists?

 

[tjwilliams25]

First of all, backup your original iTunes .xml, which unless it's changed, should be in the default Music folder. Since you've probably already opened iTunes and it's already created an .xml file, just replace it with a copy of your old one. This keeps your library in the exact order that it was in before. Now, tell iTunes where your library is (which in your case would be on the other internal drive). Try to play a song. It may need to be directed to the right location the first time, but it'll automatically find the rest of your library after the first one.

As for the odd ducks, make sure you have manually manage library enabled, and then just select consolidate library under File/Library. It'll move those files into your set library folder.

 

[Riku7]

My old computer's hard disks were starting to break so to make file transfer easier, for now, those old disks reside inside my new computer and are accessible. Original .xml backups would be there.

So is that the iTunes Music Library.xml at Users/user/Music/iTunes ?
In that same directory, there's a file called iTunes Library.itl whose last date of modification matches with the date of when I last used my old computer. Relevant or trash?
There also exists a folder called "Previous iTunes Libraries" with various .xml files in, relevant or trash?
And Album Artwork folder – I thought that album artwork got embedded into the mp3 files' metadata and not separately, relevant or trash?

I'm a bit confused by what the word library really refers to, it seems somewhat inconsistent. So did I understand correctly: Regardless of where my iTunes media is – the mp3s et cetera – the library .xml file is always saved, updated and kept at Users/user/Music/iTunes? And when iTunes asks to choose what library to use, it's not in fact asking for the iTunes media folder location, but just that .xml file? And then, the location of the media is a separate thing altogether, something that iTunes will ask when you try to play back a track.

I'll make "a few duplicates" of everything and see if I'll succeed!

 

[tjwilliams25]

Exactly, they use the word library very loosely. Your music "library" is actually split into parts: the media and the "library" files that keep track of all of the changes. That's why, if you want to keep your library exactly how you like it, you have to keep track of the library files in the Music folder. I believe that the .itl is actually what they use now with the newer versions of iTunes, so keep and duplicate that. The previous libraries are backups of the library .xml's that are made when you install a new version of iTunes. Any album artwork that is downloaded in iTunes is actually cached into that folder, and not embedded into the metadata of the actual media, so I would also keep that as well. You can choose to embed the artwork into each file manually, but I've found that's only really helpful when iTunes pulls the wrong artwork from the Store.

 

[Riku7]

Okay, to be sure, basically copypastereplaced all files in the User/music/iTunes folder. When it asks to specify a library to use, the .xml files are greyed out and the only file that I can choose is the .itl. Apparently.
Excellent, I see my playlists, smart playlist "recently added" appears to make sense, the tracks play, and "show in Finder" reveals that the songs being played indeed exist on the new HD now.

Umm, not entirely sure about that consolidating thing now though; This is what my menus look like:

And what Organize Library gives me is this:

Looks a bit dodgy, is that actually the option that I want to do? If I had to simply guess what that meant, my first guess would be that it would take the files in the non-default location of the media files, and make copies of all of that into user/music/iTunes. But if I choose that option, does it prompt me with settings to allow me to specify that it's actually the odd junk in the default location that I wish to move into the non-default one and not vice versa?

I disabled iTunes fetching missing album artwork manually, because sometimes when I'd skip a song that was beginning to play, iTunes would finish off the artwork fetching procedure by placing the skipped song's artwork to the next track instead, so I ended up with (not many), but a regular pattern of incorrect artworks until I turned off the feature. Also, the databases of iTunes tends to favor new reissues and compilations and other stuff like that which is annoying when you'd really like to get the most original and "old" version of cover art that can possibly exist. In fact, just like I prefer to specify a genre per track instead of a genre per entire album, with my favorite music I also fetch individual cover art for individual songs, rather like an illustration that best portrays the mood of that specific track.

 

[tjwilliams25]

It looks like it's changed since I've used it last. You may have to consolidate your library by manually moving everything into the folder where you want it and then doing the play/point to location trick that I mentioned in my last post.

 

[Riku7]

This is iTunes 12.12.3.7, I got so terrified of updating the OS and especially iTunes when I realized that everything I ever liked and used so much was getting systematically broken by each update.

Oh gosh okay... That's actually going to be quite a lot of work then, I can't just copy everything in one go: If a folder with the same artist name already exists and I choose "replace", it will overwrite the whole folder instead of merging the folder's contents intelligently by filling up whatever is missing.