Hi there, somewhat late to the party, but Phil0123 asked me to take a look at your issue so here I am. One thing that strikes me from the original images is that you had your media folder set one level too deep, pointing at ../iTunes Media/Music rather than ../iTunes Media as it should be. This can potentially cause an additional /Music folder to be created before you get to the artist folder level, and may confuse things when moving between iTunes and Music. See also Managing your Mac media libraries - Apple Community where I cover the standard layout of the Music library.
Regarding the Time Machine icon here is a quick YouTube link that shows how you might fix that: https://www.youtube.com/watch?v=ZnSiJYLW8Jw. TLDR, delete the hidden .VolumeIcon from the drive, empty the trash, and the misleading icon should no longer show up.
This is my general boilerplate on fixing broken tracks:
The "missing file" issue with exclamation marks happens if the file is no longer where iTunes or Music expects to find it. Possible causes are that you or some third party tool has moved, renamed or deleted the file, one of its parent folders, the drive it lives on has had a name change, or you've moved a non-portable library to a different path (see Make a split library portable for details). It is also possible that iTunes or Music have changed from expecting the files to be in the pre-iTunes 9 layout to post-iTunes 9 layout, or vice-versa, and so is looking in slightly the wrong place, or that you've been too aggressive when deleting duplicates at some point.
Select a track with an exclamation mark, use Cmd-I to get Song Info, then click No when asked to try to locate the track. Look on the file tab for the location the library thinks the file should be. Now take a look around your hard drives. Hopefully you can locate the track in question. If a section of your library has simply been moved, a folder renamed, or a drive label has changed, it should be possible to reverse the actions. If the difference between the two paths is an additional Music folder in one path then this is a layout issue. I can explain further if that is the case. If everything is where it is supposed to be try Repair security permissions for iTunes for Mac - Apple Community.
In some cases the library may be able to repair itself if you go through the same steps with Get Info, or when playing a track, but this time click Locate and browse to the lost track. It may then offer to attempt to automatically fix other broken links. Although it says something like "use the same location" I think it expects to find the tracks in the same artist & album layout they were in previously, with one systematic change to the path.
<Edit> The library needs to be aware that multiple tracks are broken (though it doesn't need to be all of them) before it will offer to try to repair multiple broken tracks. Each time the app starts up it assumes that every track is going to be where it is expected to be, so you must make sure that several tracks are marked as missing before attempting this type of repair. </Edit>
If you want me to try to provide specific advice please post back the following details:
- The location of the media folder under iTunes|Music > Preferences > Advanced
- The location of a sample missing track shown under Song Info > File > Location that begins file://
- The true path to the file whose details you gave in 2
See also FixLinks - an AppleScript to repair broken links in Music - Apple Community.
tt2