Allow selecting either tags or genres in the includes, defaulting to genres (#5874)

Genres is a filtered list based on what musicbrainz considers a genre,
tags are all the user-submitted tags. [1]

1.
https://musicbrainz.org/doc/MusicBrainz_API#:~:text=Since%20genres%20are,!).

beetsplug/musicbrainz.py

@@ -90,6 +90,7 @@ RELEASE_INCLUDES = list(
         "isrcs",
         "url-rels",
         "release-rels",
+        "genres",
         "tags",
     }
     & set(musicbrainzngs.VALID_INCLUDES["release"])
@@ -370,6 +371,10 @@ def _merge_pseudo_and_actual_album(
 
 
 class MusicBrainzPlugin(MetadataSourcePlugin):
+    @cached_property
+    def genres_field(self) -> str:
+        return f"{self.config['genres_tag'].as_choice(['genre', 'tag'])}-list"
+
     def __init__(self):
         """Set up the python-musicbrainz-ngs module according to settings
         from the beets configuration. This should be called at startup.
@@ -382,6 +387,7 @@ class MusicBrainzPlugin(MetadataSourcePlugin):
                 "ratelimit": 1,
                 "ratelimit_interval": 1,
                 "genres": False,
+                "genres_tag": "genre",
                 "external_ids": {
                     "discogs": False,
                     "bandcamp": False,
@@ -723,8 +729,8 @@ class MusicBrainzPlugin(MetadataSourcePlugin):
 
         if self.config["genres"]:
             sources = [
-                release["release-group"].get("tag-list", []),
+                release["release-group"].get(self.genres_field, []),
-                release.get("tag-list", []),
+                release.get(self.genres_field, []),
             ]
             genres: Counter[str] = Counter()
             for source in sources:

docs/changelog.rst

@@ -13,6 +13,8 @@ been dropped.
 New features:
 
 - :doc:`plugins/ftintitle`: Added argument for custom feat. words in ftintitle.
+- :doc:`plugins/musicbrainz`: Allow selecting tags or genres to populate the
+  genres tag.
 - :doc:`plugins/ftintitle`: Added argument to skip the processing of artist and
   album artist are the same in ftintitle.
 - :doc:`plugins/play`: Added `$playlist` marker to precisely edit the playlist

docs/plugins/musicbrainz.rst

@@ -32,6 +32,7 @@ Default
         ratelimit_interval: 1.0
         extra_tags: []
         genres: no
+        genres_tag: genre
         external_ids:
             discogs: no
             bandcamp: no
@@ -136,6 +137,12 @@ Default
     ``beatport_album_id``, ``deezer_album_id``, ``tidal_album_id``). On re-imports
     existing data will be overwritten.
 
+.. conf:: genres_tag
+    :default: genre
+
+    Either ``genre`` or ``tag``. Specify ``genre`` to use just musicbrainz genre and
+    ``tag`` to use all user-supplied musicbrainz tags.
+
 .. include:: ./shared_metadata_source_config.rst
 
 .. _building search indexes: https://musicbrainz.org/doc/Development/Search_server_setup

test/plugins/test_musicbrainz.py

@@ -65,6 +65,8 @@ class MBAlbumInfoTest(MusicBrainzTestCase):
             ],
             "date": "3001",
             "medium-list": [],
+            "genre-list": [{"count": 1, "name": "GENRE"}],
+            "tag-list": [{"count": 1, "name": "TAG"}],
             "label-info-list": [
                 {
                     "catalog-number": "CATALOG NUMBER",
@@ -515,6 +517,26 @@ class MBAlbumInfoTest(MusicBrainzTestCase):
         d = self.mb.album_info(release)
         assert d.data_source == "MusicBrainz"
 
+    def test_genres(self):
+        config["musicbrainz"]["genres"] = True
+        config["musicbrainz"]["genres_tag"] = "genre"
+        release = self._make_release()
+        d = self.mb.album_info(release)
+        assert d.genre == "GENRE"
+
+    def test_tags(self):
+        config["musicbrainz"]["genres"] = True
+        config["musicbrainz"]["genres_tag"] = "tag"
+        release = self._make_release()
+        d = self.mb.album_info(release)
+        assert d.genre == "TAG"
+
+    def test_no_genres(self):
+        config["musicbrainz"]["genres"] = False
+        release = self._make_release()
+        d = self.mb.album_info(release)
+        assert d.genre is None
+
     def test_ignored_media(self):
         config["match"]["ignored_media"] = ["IGNORED1", "IGNORED2"]
         tracks = [