MusicBrainz artist ID misattribution

[eliasbe]

Description

When scanning albums with multi-value MUSICBRAINZ_ALBUMARTISTID tags (semicolon-separated, as written by MusicBrainz Picard / beets), LMS takes the first ID and assigns it to the combined artist contributor. This ID then acts as a global lookup key, so any subsequent album with that same MusicBrainz Artist ID gets attributed to the wrong contributor.

This is scan-order dependent. Whichever artist contributor gets created first "claims" the shared MB ID.

To Reproduce

1. Have a local library with solo albums by an artist and a collaborative album (in my case it was Björk and Björk & Tríó Guðmundar Ingólfssonar). The collaborative album's files should have a multi-value MUSICBRAINZ_ALBUMARTISTID where the first ID is the solo artist's
2. Scan the library. -> All the artists albums should be organized under whichever contributor was scanned first.
3. Change the folder name so that the scan order changes. -> Now all the artists albums should be organized under the other contributor.

In my specific case all of Björk's solo albums showed up under "Björk & Tríó Guðmundar Ingólfssonar" in the web UI. When I changed the name of the directory for the trio and rescanned, all the albums were listed under Björk, including the collaborative one.

I verified this by querying library.db since all the tags looked clean. There was one outlier without a musicbrainz id that gave it away.

Expected behavior

I expected albums with ALBUMARTIST=Björk to be attributed to contributor "Björk", regardless of scan order.

LMS should not use a single ID from a multi-value MUSICBRAINZ_ALBUMARTISTID field as the canonical ID for a combined artist. Either parse all IDs and match appropriately, or prefer the ALBUMARTIST text tag for contributor assignment and use MB IDs only for the matching artist.

System Information:

• OS: Proxmox LXC container
• Hardware: x86_64
• Web skin: Material
• Browser: chromium
• LMS Version: 9.1.0

Additional context

I fixed my specific case by swapping the MB IDs on the collaborative album and it's working fine. But I thought you should know about this.

[mikeysas]

This is common area of confusion for new users to Lyrion. There is much discussion on this in the forum including recommendations for Picard config to ensure alignment of Artist and ID’s or many here choose to remove the Artist & Album Artists ID’s from their tags if you don’t have another reason for them.

Here is an example of a recent thread but there are many more with more detailed explanations if you search.

https://forums.lyrion.org/forum/user-forums/ripping-encoding-transcoding-tagging/1816764-lms-metadata-scaan-overrides-local-tags

FYI - you will get much better support on the forum than here.

[eliasbe]

Thank you for your reply!

I've been using Lyrion for some years (and loving it) without experiencing this. I don't remember exactly when this started but I suspect it was after some storage changes to the music library (and thus, most likely, the scan order of the library files).
I only really used Picard to fix this single example, all other tags come from beets.

I don't understand what my confusion is, is it that multivalue MB ids should have a different format than mine?
If this is expected behavior you can close this issue.
I don't really need support, I just thought it would be appropriate to share this since I put in the time to find the cause. I'm happy as long as my albums aren't attributed to incorrect artists.

[eliasbe]

Ok, I think I see now that it suits LMS better to have multiple ID fields rather than a combined field.
This doesn't matter enough to me tag my files that way. I still think this is unexpected behavior but I guess it is known behavior so this can be closed.

[mikeysas]

Ok, I think I see now that it suits LMS better to have multiple ID fields rather than a combined field. This doesn't matter enough to me tag my files that way. I still think this is unexpected behavior but I guess it is known behavior so this can be closed.

I don't think that is the issue. I recommend taking your questions to the forum as you will get better help there from a wider audience than looks here.

The challenge here is the way MB stores Artists that populate ARTIST and ARTISTS tags and the fact that LMS only reads ARTIST tag (same concept for AlbumArtist also). MB has display name like "Björk Guðmundsdóttir & Tríó Guðmundar Ingólfssonar" that populate the ARTIST tag and then populate the ARTISTS tag with the multiple values "Björk Guðmundsdóttir"; "Tríó Guðmundar Ingólfssonar" which align to the two Artist ID's that are also tagged as multi values. The issue is that LMS was only designed to read the ARTIST tag which has a single value and hence maps that with the first ID value. I am not a beets user, but if you have beets replace the ARTIST tag with the values from ARTISTS that was imported from MB, then you will have two name values mapping two ID's correctly in LMS.

There is a recommended script for Picard users and I assume something similar can be done in beets as I understand it to be a very flexible tool.

Please keep in mind that LMS existed before MB was widely used for tagging and admittedly the addition of support for MBIDs which was added much later in is not perfect, but with careful management of the tags is workable. I would also argue that MB itself is imperfect. Just ask any jazz fan that does not want their Miles Davis collection to be artificially separated by the releases that MB tags with "Miles Davis Quintet" as a separate ID from "Miles Davis".