Plex uses the ‘Album Artist’ metatag much more than other software.
Whenever you have a folder full of unclassified music
or if you have an album with guest musicians
(i.e. every time when there are different ‘[Track]Artists’ set)
you must set the ‘Album Artist’ meta tag to an identical value for all tracks which make up an album.
After correcting metatags, the Plex Dance “light” is required.
(“light” means, step 4 can be omitted)
Here are some tips regarding music
multi-disc albums
https://forums.plex.tv/discussion/comment/1050849/#Comment_1050849
handling singles and EP’s
https://forums.plex.tv/discussion/comment/1093611/#Comment_1093611
possible ‘side car’ files for music
https://forums.plex.tv/discussion/comment/1319703/#Comment_1319703
soundtracks and ‘various artists’
https://forums.plex.tv/discussion/comment/1472799/#Comment_1472799