No Musicbrainz ID (266) playlist returns entire libary of tracks

[jimbob1001]

Hello,

First of all, thanks for creating this tool - it's really awesome!

I tried the no musicbrainz ID (266) playlist but found it simply returns the entire library

PLAYLIST JSON

  {
    "name": "No MusicBrainz ID",
    "comment": "Tracks missing a MusicBrainz ID \u2014 candidates for Picard tagging",
    "all": [
      {
        "contains": {
          "mbz_recording_id": ""
        }
      }
    ],
    "sort": "+artist,+album,+track"
  }

All tracks in my library are tagged through musicbrainz picard so this result was unexpected. Below is the relevant tags from a random track that shows up in the playlist despite having the recording id tag. Not sure if it's relevant but note the confusing difference of tag names between picard and navidrome...

EXAMPLE FILE
  Music/Elder/Omens (2020)/03 - Halcyon.flac

TAGS IN FILE (FROM MUSICBRAINZ PICARD)...
  musicbrainz_recordingid: 7bc1af94-e1c1-43eb-a86e-07502905781a
  musicbrainz_trackid: 5d9865e1-2f1f-483a-ae0b-2f2830c5c9ca

RAW TAGS IN NAVIDROME...
  musicbrainz_releasetrackid:	5d9865e1-2f1f-483a-ae0b-2f2830c5c9ca
  musicbrainz_trackid:	7bc1af94-e1c1-43eb-a86e-07502905781a

What makes it even more confusing is musicbrainz own documentation seems to be a mess in terms of the MBID name & mapping for trackID & releaseID!

MUSICBRAINZ OFFICIAL TAG MAPPING DOCUMENTATION

  MusicBrainz Track ID
    Internal Name = musicbrainz_trackid
    ID3v2 = TXXX:MusicBrainz Release Track Id
    Vorbis = MUSICBRAINZ_RELEASETRACKID
    APEv2 = MUSICBRAINZ_RELEASETRACKID
    iTunes MP4 = ----:com.apple.iTunes:MusicBrainz Release Track Id
    ASF/Windows Media = MusicBrainz/Release Track Id
    RIFF INFO = n/a

  MusicBrainz Recording ID
    Internal Name = musicbrainz_recordingid
    ID3v2 = UFID:http://musicbrainz.org
    Vorbis = MUSICBRAINZ_TRACKID
    APEv2 = MUSICBRAINZ_TRACKID
    iTunes MP4 = ----:com.apple.iTunes:MusicBrainz Track Id
    ASF/Windows Media = MusicBrainz/Track Id
    RIFF INFO = n/a

And just for completeness here is how navidrome docs say the tags are mapped...

NAVIDROME TAG MAPPINGS DOCUMENTATION

  musicbrainz_trackid:
    aliases: [txxx:musicbrainz release track id, musicbrainz_releasetrackid, ----:com.apple.itunes:musicbrainz release track id, musicbrainz/release track id]
    type: uuid

  musicbrainz_recordingid:
    aliases: [ ufid:http://musicbrainz.org, musicbrainz_trackid, musicbrainz track id, ----:com.apple.itunes:musicbrainz track id, musicbrainz/track id ]
    type: uuid

[jimbob1001]

Follow up...

I've created a missing lyrics (222) and a missing genre (267) and they also return the entire library...

{
  "name": "Missing Lyrics",
  "comment": "Loved tracks without embedded lyrics \u2014 candidates for lyric tagging",
  "all": [
    {
      "contains": {
        "lyrics": ""
      }
    }
  ],
  "sort": "+artist,+album,+track"
}

{
  "name": "Missing Genre",
  "comment": "Tracks with no genre tag \u2014 the uncategorised wilderness",
  "all": [
    {
      "contains": {
        "genre": ""
      }
    }
  ],
  "sort": "+artist,+album,+track"
}

[jimbob1001]

Looks like there is already some existing discussions regarding this on the navidrome github

@[nano9g](https://github.com/nano9g)
nano9g
[4 days ago](https://github.com/navidrome/navidrome/discussions/5255#discussioncomment-16536401)
I just found this https://github.com/navidrome/navidrome/discussions/4728#discussioncomment-15068234 that does work. The solution is unintuitive to be sure, so to recap:

🟢 Tracks that do have the tag
{ "all": [{"contains": {"mycustomtag": ""}}] }
🚫 Tracks that do not have the tag
{ "all": [{"notContains": {"mycustomtag": ""}}] }
Hopefully this helps someone else who comes looking for it in the future.

I tried the above solution but for me using "contains": {"lyrics": ""} returns the entire library, while using "NotContains": {"lyrics": ""} returns zero tracks so completely none-the-wiser at this point!

Also looks like a fix is maybe in the works here

Description
Add a new isMissing operator for smart playlists that detects whether a tag or role is absent from a track's metadata. This addresses a common need for library maintenance — e.g., finding all tracks missing ReplayGain data or genre tags.

The operator only supports tag and role fields (stored as JSON in the database), where absence is unambiguous — the JSON path either exists or it doesn't. Regular DB column fields are not supported, as their "missing" semantics are ambiguous (NULL vs zero vs empty string).

Example NSP usage:

{"all": [{"isMissing": {"replaygain_album_gain": true}}], "sort": "album,tracknumber"}
{"all": [{"isMissing": {"genre": false}}], "sort": "title"}
{"all": [{"isMissing": {"artist": true}}], "sort": "title"}