Multi-artist albums and tracks

Sporiff

Hi everyone o/

One of the most requested features we know of is the multi-artists album. As a bit of background for those who don't know: Funkwhale albums can only be associated to a single artist. The tracks contained within the album might be associated to different artists, but the album itself can only be one. Similarly, each track may only be associated to one artist, so tracks "feat." another artist are not properly attributed.

In the MusicBrainz world, we refer to this as a "Various Artists" album. To fulfill the single artist requirement in the database, the album should be tagged as "Various Artists". The problem is that this creates a false impression of the library, with a pseudo artist named "Various Artists" having a lot of albums attributed to them. Worse still, when content not tagged with Picard is introduced, multi-artist albums sometimes end up with a single "artist" consisting of a comma-separated list of artists:

"albumArtist": "artist1,artist2,artist3,artist4"

A valiant attempt was made to try and update Funkwhale's schema to support multiple different artists per album and track so that we can more accurately portray compilation albums, but it's clear that this is something we need to step back from and spec out before we can approach it. Now that API v2 is officially on the cards, it's as good a time as any to think about it 😃

Let's brainstorm our ideas here so we can start speccing the feature out 💪

wvffle

How about dividing uploading and importing into 2 distinct sections? Currently it looks like a single unified action. If we divided it so that user sees what's being uploaded and what's being imported in 2 different tabs, we may introduce a middle-step which is tagging untagged/mistagged uploads. The flow would look like:

User drops file to upload box
It is queued (in browser) to upload, user can move to another page
User receives notification whether the file is uploaded or errored or needs tagging (User can disable each type of notification in settings)
If upload is mistagged, user needs to tag it correctly in our UI, the case of "albumArtist": "artist1,artist2,artist3,artist4" can be handled manually by user.
Correctly tagged upload is queued to import
User receives a notification if the import failed

Users can check anytime their upload and import queues in respective tabs.

That way whenever we detect a coma in albumArtist field, we can ask user to set the artist to multiple artists, eventually create a new artist from the same view just to have it in the album.

Sporiff

wvffle I definitely agree with giving users the opportunity to tag items in the app to avoid issues. We would need to consider the following:

What about users who are uploading content using the Funkwhale API? Would we simply return a link to the frontend saying they need to go and fix issues?
If I upload 1000 tracks, and all of them require editing, how feasible is this? We would need bulk edit tools, for sure, but I don't think this is the end solution.

The ID3 tag schema does have a preferred way of delimiting things using null markers. This at least should be properly supported for automatic uploads.

petitminion

wvffle isn't this out of the scope of this feature ? The problem here is about how to handle multiple artist per album. For me allowing user to tag their content in the ui is a more general feature. And impov it's a loooot of work to do something that is already done by other softwares.

I think we all agree to follow the musicbrainz tag specification ?
In this case backend implementation : we investigate if it's possible to follow musicbrainz implementation. And how.
Frontend implementation: do we want to show a list of artists in the album card ? Or do we keep "various artists" ?

wvffle

petitminion wvffle isn't this out of the scope of this feature?

Yes, it is. I'm just suggesting some kind of a solution to the problem of mistagged uploads.

Sporiff If I upload 1000 tracks, and all of them require editing, how feasible is this? We would need bulk edit tools, for sure, but I don't think this is the end solution.

How would you bulk edit the track titles? I've recently dug through ₄₀₀ documents from my email. It took a while, but if I wanted to have all the invoices, contracts, receipts and other stuff organized and categorized, I had to do it. I believe same logic applies to a music library. If you want to have everything categorized well - you have to do the job tagging.

If we don't want to deal with bulk editing, after a first untagged file is uploaded, we may stop the upload queue, show a warning that informs the user that the upload queue contains untagged files and ask whether he wants to proceed or cancel the upload queue suggesting that he should use some recommended software that can bulk edit the files.

heyarne

i agree with regarding the musicbrainz as the de-facto standard. a lot of thought has gone into it and it enables compatibility with a wide ecosystem. there is some information about multi-value tags in the picard documentation. one thing that musicbrainz supports that will be problematic to parse from raw id3 is join phrases (e.g. "Artist A. & Artist B feat. Artist C", where & and feat. both exist as join phrases in the musicbrainz database), but maybe that's something we have to live with.

petitminion Frontend implementation: do we want to show a list of artists in the album card ? Or do we keep "various artists" ?

there's the album artist id3 tag that may be used for this in the album overview? the track detail at the moment is not that front and center, but the track artists there would still make sense imo

petitminion

Front

If files are mb tagged :
1.1 Album card : I would use Various Artists artist name. But I would include the albums in every artist page who is present in the album. I would also create a special "Various Artist" artist page, with an explanation of what is happening haha
1.2 Track card : show the Artist Sort order tag (seems to contain & or feat in the right order : tried in various songs but can't find doc about this tag)
For file not tagged with mb
I would not support because we can find how it will be tagged. If the front is messy and the admin want to solve this thay would have this feature : https://forum.funkwhale.audio/d/243-new-feature-only-allow-musicbrainz-tagged-file-to-be-uploaded/5

Back :

For mb tagged file :
1.1 Add Artist Sort order to the track model
1.2 Create foreign key from the various artist album to each of the artist present in the release.
For file not tagged with mb
No support

This might be usefull : tag map between picard, mb, id3 and other : https://picard-docs.musicbrainz.org/downloads/MusicBrainz_Picard_Tag_Map.html

ps :

some mb doc https://musicbrainz.org/doc/Style/Artist_Credits#Featured_artists
some other proposition for the back but inspiring : https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/1279#note_26180
i'm trying to find how mb server handle multiple artirst. How is generate "Recording by Carnage feat. Migos" from https://musicbrainz.org/recording/b4c3bd3c-f575-4d51-9327-fcad28a10961/edit ? -> https://github.com/metabrainz/musicbrainz-server/blob/47b118a69b5933a26423d9cdad25a6365bc590c9/root/recording/RecordingHeader.js -> https://github.com/metabrainz/musicbrainz-server/blob/master/root/static/scripts/common/components/ArtistCreditLink.js but Idk how to read this ^^'

heyarne

petitminion One remark: Instead of "Artist Sort Order", "Artist Credit" seems to be the tag we're looking for. "Artist Sort Order" includes formatting like "Last Name, First Name" for some artist names.

It even seems like the ARTISTS / Artist Credit / MusicBrainz Artist Id properties may in combination be used to link to the individual artists, which is pretty neat and contradicts what I said earlier. The separator between different artists in the ARTISTS field is configurable in Picard and by default provides a dropdown to pick between /, ; and /.

For example, for https://beta.musicbrainz.org/recording/6a009da8-333a-4d47-bd66-64b2886ad6bc (which has lots of different artists and join phrases) the tags look like this after I've tagged them with Picard (retrieved via kid3-cli -c 'get all'):

File: MPEG 1 Layer 3 320 kbps 44100 Hz Joint Stereo 3:59
  Name: 01 Chance the Rapper feat. BJ the Chicago Kid, Lili K., Kiara Lanier, Peter Cottontale, Will for The O'mys & JP Floyd for Kids These Days - Good Ass Intro.mp3
Tag 1: ID3v1.1
  Title         Good Ass Intro
  Artist        Chance the Rapper feat. BJ the
  Album         Acid Rap
  Date          2013
  Track Number  1
Tag 2: ID3v2.3.0
  Title                              Good Ass Intro
  Artist                             Chance the Rapper feat. BJ the Chicago Kid, Lili K., Kiara Lanier, Peter Cottontale, Will for The O'mys & JP Floyd for Kids These Days
  Album                              Acid Rap
  Date                               2013-04-30
  Track Number                       1/13
  Genre                              Hip Hop
  Album Artist                       Chance the Rapper
  BPM                                80
  Disc Number                        1/1
  Encoder Settings                   Lavf52.54.0
  ISRC                               QMEZE1949600
  Language                           eng
  Media                              Digital Media
  Original Date                      2013
  Picture                            
  Publisher                          [no label]
  Sort Album Artist                  Chance the Rapper
  Sort Artist                        Chance the Rapper feat. BJ the Chicago Kid, Lili K, Lanier, Kiara, CottonTale, Peter, Will for The O'mys & Floyd, J.P. for Kids These Days
  ARTISTS                            Chance the Rapper/BJ the Chicago Kid/Lili K./Kiara Lanier/Peter Cottontale/Will/JP Floyd
  Album Artist Credit                Chance the Rapper
  Artist Credit                      Chance the Rapper feat. BJ The Chicago Kid, Lili K., Kiara Lanier, Peter Cottontale, Will for The O'mys & JP Floyd for Kids These Days
  MusicBrainz Album Artist Id        373a4c98-a46b-48e4-86ec-f6ca65b4f438
  MusicBrainz Album Id               8caabc0f-8c2a-4060-893f-f71bc93cc073
  MusicBrainz Album Release Country  XW
  MusicBrainz Album Status           official
  MusicBrainz Album Type             album/mixtape/street
  MusicBrainz Artist Id              373a4c98-a46b-48e4-86ec-f6ca65b4f438/112beffb-1adc-488b-8d61-7b2ab3475d52/6fb4d2e7-f544-4a4c-aca5-63748df5de72/cee927f3-418b-487f-855a-98bf97516954/94223d29-2a1a-452c-81dc-62d21acf2f8a/d4e6bbf8-a34d-427b-a317-c614f405acd0/28b82bca-f692-4655-9c22-41d8fc1d7391
  MusicBrainz Release Group Id       02a9a0f7-8945-436f-8eca-144f94de1518
  MusicBrainz Release Track Id       222d8f34-69bb-4fa8-a755-2ba31af82bbd
  REPLAYGAIN_ALBUM_GAIN              0.00 dB
  REPLAYGAIN_ALBUM_PEAK              0.000000
  REPLAYGAIN_TRACK_GAIN              0.00 dB
  REPLAYGAIN_TRACK_PEAK              0.000000
  SCRIPT                             Latn
  Script                             Latn
  originalyear                       2013
  File ID: musicbrainz               6a009da8-333a-4d47-bd66-64b2886ad6bc
  ```

[deleted]

petitminion I'm sorry I still don't understand ^^' sets what record ? And why do you speak about picard ? we just care about mb tags don't we ?

MusicBrainz Picard is the official tagger of MusicBrainz. It's the tagger everyone uses when they need the MusicBrainz tags because they're front and center on Picard.

And I mean Funkwhale takes the first spelling it learns about and reuses it for all other tracks and releases with the same MBID for the artist.

This is currently also a problem because Funkwhale takes the first tag value and discards the rest of the values, and the database gets screwed up because it won't import the tags again after reuploading because the music files have an MBID for the release and the track itself. Funkwhale identifies it and reuses the data it already had.

petitminion don't think we support this. We should create another issue for this.

Well the only solutions that come to mind is querying the MusicBrainz database and I think there was a discussion about it, where people were afraid everyone would do it for their whole library and overwhelm the servers right after the hypothetical update rolls out.

petitminion okey interesting also but I don't get your point. What are you proposing about this tag ?

To use it. Um. I could have sworn someone here was trying to figure out how to calculate one for singles and ignore the provided tag. If that person comes around I'll bring it up again.

heyarne The separator between different artists in the ARTISTS field is configurable in Picard and by default provides a dropdown to pick between /, ; and /.

This is a fallback. The ARTISTS tag is almost always a multivalue tag, that's the whole reason it exists. Please double click the tag in Picard; if it's multivalued it will open up a window to edit each value separately. If it's single-valued it will make you edit it right in the table.

heyarne

I'd suggest the following for mb-tagged tracks (based on the tags that are set by Picard):

If track is MB-tagged := At least one UUID in MusicBrainz Artist Id
- Separator string := First series of characters in MusicBrainz Artist Id that are not matched by [a-f0-9]{8}-([a-f0-9]{4}-){3}[a-f0-9]{12}
- In addition to artist, introduce new property artists (for albums and tracks): An array of objects that look like the current artist object (see below), but has an optional additional property join_phrase that contains a string to add after an artist name. it may not be set / be null / contain an empty string (i'm not sure how the rest of the funkwhale api handles optional values; this should be handled following the convention)
  - join_phrase, id and fid can be inferred roughly like this (for tracks; property names for albums will be different):
    - mbids = id3["Musicbrainz Artist Id"].split(SEPARATOR_STRING), which can be mapped to internal funkwhale artist ids
    - artist_names = id3["ARTISTS"].split(SEPARATOR_STRING), which gives the artist names as they appear in Artist Credit
    - artist_names and can then be used to figure out the Join-Phrases
  - … putting it back together in the frontend is simpler.
If track is not MB-Tagged: Use artistas before.

From what I can tell, this requires the backend to parse Artist Credit, ARTISTS and MusicBrainz Artist Id for individual tracks and Album Artist Credit, MusicBrainz Album Artist Id and Album artist for albums (Note: I could not find a file with tags for multi-artist albums, so the second part needs some additional scrutiny).

All of this should be backwards-compatible and at the same time bring feature-parity with everything the mb-tagging scheme for multiple artists allows, especially nicely-formatted links for multiple artists that don't make a lot of assumptions how join phrases are used (see the "Track Artist" column on https://beta.musicbrainz.org/recording/6a009da8-333a-4d47-bd66-64b2886ad6bc for an example).

NB: There's an edge case I noticed that occurs if an artist in ARTISTS is the same as a join phrase. An artist named feat. for example would cause a link to appear in the wrong place. I don't know how musicbrainz handles this.

NB2: This exceeds the original "Various Artists" prompt, but maybe we can just try to solve split EPs and other cases that go beyond compilations?

Current artist object:

{
	"artist": {
		"id": 1214,
		"fid": "https://.../federation/music/artists/39bb73ba-d9b3-4202-a6fe-0a531c22eb78",
		"mbid": "7717539b-33aa-45d5-b88d-9e627172db19",
		"name": "Tocotronic",
		"creation_date": "2022-05-18T12:37:45.769935Z",
		"modification_date": "2022-05-18T12:37:45.770077Z",
		"is_local": true,
		"content_category": "music"
	}
}

petitminion

heyarne NB: There's an edge case I noticed that occurs if an artist in ARTISTS is the same as a join phrase. An artist named feat. for example would cause a link to appear in the wrong place. I don't know how musicbrainz handles this.

this is an issue. I think the magic is here but I can't find where : https://github.com/metabrainz/musicbrainz-server/blob/master/root/static/scripts/common/components/ArtistCreditLink.js

petitminion

In a mb tagged file we have :
artist tag = artist credit = a string containing the artists with match phrase
Artists tag = a list of artist with a (unknown ?) separator
Musicbrainz Artist Id = a list of artist mbis's.

So why not user artist tag to get the join phrase (used in the frontend) and then use Musicbrainz Artist Id to match the artists from the track to our db ? We could even do a simple regex in the front to generate a link to the artist page from the artist string. This way we don't care about the Artists separator and the artist join phrase

exemple :
artist = MZ feat. Chich & Marlo
Artists = MZ/Chich/Marlo
Musicbrainz Artist Id = 8b289152-df47-4870-b204-5b0c94a88f32/19961461-c692-46e3-bf37-4c76975b2baf/85649d1c-f528-45dd-b6bd-67139db646d0

Easy to find MZ in "MZ feat. Chich & Marlo" and link it to our db

petitminion

petitminion So why not user artist tag to get the join phrase (used in the frontend) and then use Musicbrainz Artist Id to match the artists from the track to our db ? We could even do a simple regex in the front to generate a link to the artist page from the artist string.

So even if we implement multiple artist spelling this still applies since we can regex for every spelling we have in db. There is a risk of homonyms but it's very low don't you think ? And it can be manage by the front

[deleted]

Hello. I've been waiting for this for a while and decided to chime in.

I might be getting confused here, but the ARTISTS tag is multivalued. It doesn't have a separator because the artists are already separated, you don't need to parse it. (Unless it's a tag format that doesn't support multivalued tags like APE. Picard uses '; ' in such cases.)

Second, we simply definitely need a script to place in the Picard script section to avoid having to fix all artist tags manually after import. They're not very hard to make. I could whip one for you that uses standardized artist names and replaces the ARTISTS fields (and/or the ARTIST field since all fields are multivalue capable). This will make things faster for anyone just starting to populate their repo and I use one like that for Lollypop as well.

This would give us the problem where artist credit is replaced but we can fix that with the ARTIST tag in the script too. Mainstream streaming services no longer use concatenation anyways, not as a golden standard anyways. I know Apple Music supports it but these days artists no longer bother using the feature.

The bottom line is, Picard CAN fetch these values. It just doesn't write them unless asked to.

Third, singles already have an ALBUMARTIST tag. Sometimes it doesn't even match the artist in the single, and sometimes they have mismatching tracks as well. For artist intent I would very much prefer Funkwhale to leave that alone on all cases.

petitminion

[deleted]

I might be getting confused here, but the ARTISTS tag is multivalued. It doesn't have a separator because the artists are already separated, you don't need to parse it. (Unless it's a tag format that doesn't support multivalued tags like APE. Picard uses '; ' in such cases.)

nice to know o/

avoid having to fix all artist tags manually after import.

why we should have to do fix artists tags ?

[deleted] Third, singles already have an ALBUMARTIST tag

I'm not shure how fw handle the album artist. What you are proposing is to use artist and not albumartist ?

[deleted]

petitminion why we should have to do fix artists tags ?

MusicBrainz stores multiple spellings for each artist, these vary relase-to release and even within a single release. They also have different localizations and sometimes they're completely different aliases.

Currently importing a track on Funkwhale sets the record for all the rest of the tracks to follow. This might be undesired behaviour but it requires manual intervention since Picard doesn't fix this on the ARTISTS tag (though it does have a toggle to use standardized names for the ARTIST tag. [well, now that i think about it, it probably affects the ARTISTS tag too. would be good to document this. will report back])

petitminion I'm not sure how fw handle the album artist. What you are proposing is to use artist and not albumartist ?

"ALBUMARTIST" is a misnomer 'cuz it doesn't apply only to albums. It applies to all releases. The only time Picard doesn't store an ALBUMARTIST tag for a matched track is when the track isn't associated with a release. Singles, compilations, everything has an ALBUMARTIST tag and in the MusicBrainz database it should always follows artist intent, the editors do everything to fill this gap.

Often results in edit wars. They're very distressing.

petitminion

[deleted] Currently importing a track on Funkwhale sets the record for all the rest of the tracks to follow. This might be undesired behaviour but it requires manual intervention since Picard doesn't fix this on the ARTISTS tag (though it does have a toggle to use standardized names for the ARTIST tag. [well, now that i think about it, it probably affects the ARTISTS tag too. would be good to document this. will report back])

I'm sorry I still don't understand ^^' sets what record ? And why do you speak about picard ? we just care about mb tags don't we ?

[deleted] MusicBrainz stores multiple spellings for each artist, these vary relase-to release and even within a single release. They also have different localizations and sometimes they're completely different aliases.

oh interesting, even if we use the artist mbid to match artists it might create bugs if the spelling is not the same. I don't think we support this. We should create another issue for this.

[deleted] "ALBUMARTIST" is a misnomer 'cuz it doesn't apply only to albums. It applies to all releases. The only time Picard doesn't store an ALBUMARTIST tag for a matched track is when the track isn't assosciated with a release. Singles, compilations, everything has an ALBUMARTIST tag and in the MusicBrainz database it should always follows artist intent, the editors do everything to fill this gap.

okey interesting also but I don't get your point. What are you proposing about this tag ?

petitminion

[deleted] And I mean Funkwhale takes the first spelling it learns about and reuses it for all other tracks and releases with the same MBID for the artist.

This is currently also a problem because Funkwhale takes the first tag value and discards the rest of the values, and the database gets screwed up because it won't import the tags again after reuploading because the music files have an MBID for the release and the track itself. Funkwhale identifies it and reuses the data it already had.

Okey yes. This could be improve but I will open another feature request for this. Thx a lot for pointing this out ! 🙂

petitminion

[deleted] To use it. Um. I could have sworn someone here was trying to figure out how to calculate one for singles and ignore the provided tag. If that person comes around I'll bring it up again.

So instead of using a generic various artists in the Ui we use albumartist tag. I'm in favour of this but we should take care to link the album to all the artists in any case for background processes.

[deleted]

petitminion So instead of using a generic various artists in the Ui we use albumartist tag.

MusicBrainz has support for placing "Various Artists" as the ALBUMARTIST tag. It even has its own MBID for those cases where the artist is a real artist called 'Various Artists" because of course that's a thing.

So if you wanna replace the name of album artists with that tag you just find the MBID 89ad4ac3-39f7-470e-963a-56509c546377 and do
the thing. But we should probably have a compilations section. And then again sometimes the artist for a compilation is actually specified:

https://musicbrainz.org/release-group/99fff6dd-cf3f-4886-bb9b-65fdd6439912

petitminion we should take care to link the album to all the artists in any case

I think that should be done in the artists' UI, yes, but we should specifically make a visible section for this like "Also appears in:" so we can look up official releases and stuff. Truth be told, whenever I need a specific track by an artist I use search, and when I need all of an artist's tracks I go to the artist's 'all tracks' section. It's informative, so it's nice to have in the same page; but at the same time, we should really keep two sections on the page for that.

petitminion So even if we implement multiple artist spelling this still applies since we can regex for every spelling we have in db. There is a risk of homonyms but it's very low don't you think ?

I do not think, no. I already have albums and artists with similar and identical names in my library; asking a full set of listeners to tell them apart when mixed up is not viable. But we already have the MBIDs for that, they're already completely disambiguated and a regex formula is not needed at all.