[HeresJohnny]

I finally realized why I have so many entries "[MISSING]" under artists and IMHO it's a design flaw. All albums that are sorted under MISSING have an empty tag "album artist". I alway only fill the field "artist" unless there are guest musicians involved in which case I put the main artist under "album artist" and enumerate other artists in the "artist" field. I also use "album artist" when classical music is involved. In this case, I use "album artist" with the classical composer's name if he's consistent throughout the album and "artist" for performers, i.e. orchestra, soloists, etc. If it's a consistent performer and different composers I switch fields. Summing up, I always put under "album artist" the person or group which is consistens throughout the whole album.

Anyways, it shouldn't be detrimental to leave "album artist" empty. Kodi should check that field first and if it's empty use the info from "artist".

Update: Btw, it doesn't matter if musicbrainz tags are present, if "album artist" is empty it still goes under MISSING.

[DaveBlake]

Split into thread of its own, sticking things on the end of my dev plan thread really isn't helpful (I have more tidy-up of that thread to do when I have time, so don't feel picked on).

I don't think you have understood why you have so many items under the "[Missing]" artist. It will not be just because you have an empty albumartist tag, but other conditions will be contributing. Kodi will work out the album artist from the artist tag providing the artist tag is the same for all the songs of the album.To diagnose more I will need to see some of your tagging.
 

Update: Btw, it doesn't matter if musicbrainz tags are present, if "album artist" is empty it still goes under MISSING.

That raises more questions about your tagging and what editing you may have done.  Picard will provide an albumartist(s) and matching MusicbrainzID tags, so how is that empty tag happening?

Show me some tagging examples, and then we can see if there is a processing flaw, a gap in wiki description or you are doing something unexpected.

[HeresJohnny]

Sorry, the last thing I want is to antagonize you. I've uploaded a few sample files, sending you PM.

[DaveBlake]

Not antagonised, usual happy self, just very short on time.

Had a brief look at your music files. The thing you are hitting is that when Kodi finds a Muiscbrainz album (release) id tag it expects the full set of Muiscbrainz id tags that it uses to be present. You could consider this a flaw, it is certainly a vulnerability, but was implemented that way back when MB integration was first introduced (Gotham?), and I have not touched it.  If you tag using Picard, which is the most common way for music files to gain mbid tags, then they will all be there.

What mbid tags are the "full set" Kodi expects? Well those listed in https://kodi.wiki/view/Music_tagging#Tags_Kodi_reads that start MUSICBRAINZ_. So those files that do not have ALBUMARTIST and MUSICBAINZ_ALBUMARTISTID tags, but do have a MUSICBRAINZ_ALBUMID tag, get a "[missing]" as the album artist. Add those tags, a repeat of the ARTIST and MUSICBRAINZ_ARTISTID tags, and all will be well.

The processing path for files tagged with mbids is completely different from that without, it would be nice to reconcile them a little more and make it even more robust. But it is also risky to start fiddling with something that generally works well, and I have many other tasks to deal with.

[DaveBlake]

Looking at big more you may have other tagging issues too.
I notice that on "Don't Ever Leave Me" you have 2 ARTIST tags but only one mbid value in the MUISICBRAINZ_ARTISTID tag, and that value "63de2e50-9aec-437c-a3af-de770d93e55f" is not found in the Musicbrainz site. That release has artists "Keith Jarrett" and "Charlie Haden", and the MUISICBRAINZ_ARTISTID = 061c4920-3ea6-4835-98f6-02f3b82f5e3a; 1f0cdc02-c8d5-4228-8227-37ec0c289b48

I strongly suggest that you use Picard to get the MusicbrainzID tags, whatever you are doing now isn't creating a consistent set of tags.

For your interest I rip using EAC (that verifies the integrity of a rip online against the AccurateRip database), then run through Picard manually ensuring that the correct release is chosen. I finish off in Mp3tag, setting genre, embedding art if Picard didn't, etc.

Happy tagging

[HeresJohnny]

I will check musicbrainz settings in foobar2000 (which is what I use to tag) and if necessary get in touch with the developer there.

[HeresJohnny]

I've uploaded another file 07 - Among Angels.24bit.flac which I've just retagged with foobar2000's musicbrainz tagger. No musicbrainz_albumartist is added by that process and only the artist field is filled (not albumartist). Sure enough, Kodi files it under MISSING. I like my music files well organized, however, I'm also not sure how I feel about having to duplicate tag info to satisfy Kodi. Kodi needs one of musicbrainz_albumartist OR albumartist to not throw a MISSING fit.

I've then dowloaded Picard and checked what tags it would add and those are quite a few ones. I'm weary to just run my whole collection through Picard, though, since often I have a certain pressing of a CD and I have no experience how good Picard is in recognizing those automatically.

Also, I use "date" for the year the recording was first issued where musicbrainz puts the year of the specific release. That would need lots of manual intervention.

[DaveBlake]

Kodi needs one of musicbrainz_albumartist OR albumartist to not throw a MISSING fit.

No that is not what I said, read it again. You need to add both MUSICBRAINZ_ALBUMARTISTID and ALBUMARTIST tags (or remove all the musicbrainz tags I guess, but that would be a shame).

I've then dowloaded Picard and checked what tags it would add and those are quite a few ones. I'm weary to just run my whole collection through Picard, though, since often I have a certain pressing of a CD and I have no experience how good Picard is in recognizing those automatically.

Also, I use "date" for the year the recording was first issued where musicbrainz puts the year of the specific release. That would need lots of manual intervention.

You can add settings that control what tags Picard adds, you do not have to have them all. I disable things like ASIN (Amazon ID) etc. You can also get it to use recording year. If Foobar has added Musicbrainz release ids accurately then Picard will  have no difficulty whatsoever getting the same release. As for automatically identifying pressing it will depend on what unqiue info it has to go on.

You have used Foobar, that has tagged inaccurately (in the example you gave me), yet you are weary of using Picard to get those tags accurately, I find that odd but up to you.

You would like Kodi to treat absent albumartist and related mbids as if the artist was the album artist. That is something that could happen, but is not going to happen in the immediate future.

[HeresJohnny]

I should have clarified: Not all my music has MB tags yet.

Also, my testing just prior to my previous post indicates that it's sufficient to add either musicbrainz_albumartistid or albumartist for Kodi to properly file it.

[Powerhouse]

I found that years ago, MusicBrainz Picard was way better at finding my rarer Music than foobar, and the fact that Kodi was going to standardize on MusicBrainz data, was all I needed to switch over. Not that I just use Kodi to listen to my Music, but I found all my other avenues of listening to Music (Car, iPod, Sonos, etc), all benefit from my MusicBrainz tags as well.