Mutiple album artists not supported

[baloe]

Related issue: MusicPlayerDaemon/MPD#2293

Bug report

Describe the bug

I have several albums with multiple album artists.
(This is often the case with jazz music where artists would collaborate on an album.)

Expected Behavior

When viewing an album artist, e.g. in Mpdroid, in MALP or in Cantata, the album should be listed for each one of the multiple album artists tagged with the songs of the album.

Actual Behavior

• Mpdroid and Cantata: The album is only shown for one of the album artists.
• MALP: There are multiple album entries for each one of the album artists, and only one of these album entries actually has tracks. When clicking on any of the other seemingly identical album entries not a single track is listed

Version

Music Player Daemon 0.24.3 (0.24.3)

Configuration

grep "^[^#]" /etc/mpd.conf prints

music_directory         "/mnt/music/files"
playlist_directory              "/mnt/music/playlists"
db_file                 "/var/lib/mpd/tag_cache"
state_file                      "/var/lib/mpd/state"
sticker_file                   "/var/lib/mpd/sticker.sql"
user                            "mpd"
bind_to_address                 "::"
port                            "6600"
save_absolute_paths_in_playlists        "no"
input {
        plugin "curl"
}
decoder {
        plugin                  "hybrid_dsd"
        enabled                 "no"
}
decoder {
        plugin        "wildmidi"
        enabled       "no"
        #config_file "/etc/timidity/timidity.cfg"
}
audio_output {
      type                    "alsa"
      name                    "SPDIF"
      device                  "hw:CARD=DAC,DEV=0"
      mixer_type              "software"
}
playlist_plugin {
    name "cue"
    enabled "false"
}

[baloe]

Unfortunately, I cannot upload a demo file to demonstrate the issue, because github won't let me upload the 3kB flac file of silence I have created. You can easily create one yourself with, e.g., audacity.

I have tagged my demo file using mutagen in python (https://mutagen.readthedocs.io/en/latest/) as I do for all my imported audio (though in a more sophisticated framework, of course).
This is the python code:

import mutagen.flac
file = mutagen.flac.FLAC("dummy.flac")
file['albumartist'] = ['Testartist 1', 'Testartist 2']
file['album'] = 'Testalbum'
file['title'] = 'dummy'
file.save()

Here is what the metadata looks like in MusicBrainz:

And this is what I get in MPDroid:

[MPconta]

@baloe
I can just repeat myself - i use MPDroid and have no issues with multi artists nor multi albumartists. Try another tagging app (e.g. Mp3tag) and look if there are changes for your use case.

[baloe]

@MPconta Don't get me wrong, I value your response. I cannot use Mp3tag, though, because they don't support GNU/Linux.

It would be interesting to have a look at one of your files.

Here is my test file: dummy.flac.
Maybe you can tag it using the tool that works for you and make it available?
Or you could have a look at the tags and tell how they are different from what your tool would produce.

Otherwise I am pretty sure that the tags are technically correct. They are picked up correctly by a bunch of local players I have tested, and by MusicBrainz. MPD+MPDroid, MPD+MALP, and MPD+Cantata all fail, which initially got me thinking that it must be an issue with MPD, but then I discovered that MPD+Plattenalbum (https://github.com/SoongNoonien/plattenalbum) picks up the tags correctly.
So it must be an issue with the MPC client or a matter of versions.

I updated my music server from Ubuntu 12 to Ubuntu 24 in December, which also upgraded the version of MPD. I think that this is where all the trouble started. Trying to resolve this issue I have updated MPD to the most recent stable version (requires compiling it from source), but that did not help.
But then, MPDroid, being quite dated, expects some older version of MPD, I guess..

[MPconta]

Well, i had a look on your file - there are 2 albumartists, album and title correctly tagged.
You know, that you can choose in MPDroid what is preferably listed - albumartist or artist? Maybe thats the reason for your problem.
Btw. why don't you use the artist-tag for the different jazz-artists on an album? Wouldn't make that things easier?

[hurzl]

The value received from mpd is correct:

file: test/albumartist/dummy.flac
Last-Modified: 2025-05-08T17:03:26Z
Added: 2025-05-08T17:05:12Z
Format: 44100:16:1
Title: dummy
AlbumArtist: Testartist 1
AlbumArtist: Testartist 2
Album: Testalbum
Time: 10
duration: 10.000

From this result MPDroid only reads a single value for the (album) artist, so the second one is ignored:

dmix/MPDroid/src/main/java/com/namelessdev/mpdroid/SearchActivity.java

Line 214 in 2c8f649

Artist artist = music.getAlbumArtistAsArtist();

Would have to rewrite all this for Lists ...

[abarisain]

I think the ancient MPD library used doesn't even support parsing multiple AlbumArtist so you'd have to fix this. The way it works, the last sentence AlbumArtist is the one taken into account