Plex currently requires you to store all albums in a folder structure like this:
/music
/album artist
/album title
01. track artist - track title.ext
02. track artist - track title.ext
03. track artist - track title.ext
...
This applies to sampler albums as well, because Plex currently has no concept of “sampler”/“compilation” albums.
Which requires the use of “Album Artist” together with “Album Title” as the unifying properties of a sampler album.
The regular compilation in Plex therefore has an Album Artist of the name “Various Artists”.
Additionally, each different Album Artist needs to have its assigned albums be stored in a separate artist folder on disk.
If this rule is violated, you suddenly see all compilations to assume the album artist from any one of the albums which are stored inside the same folder. i.e. exactly what you experienced.
Therefore for all your compilations, if they cannot be assigned to one “real” artist, do the following:
- remove them from their respective folders inside the artist folder of other artists, into a folder which is named after their common Album Artist – which means a folder name of “Various Artists” for most of them
- insert a AlbumArtist metatag with identical content into all tracks of any one album. This is not the same tag as the regular “Artist”/“TrackArtist”!
- make sure that the Album Title meta tag of every track inside a particular album has also identical content. (The “disc number” does not belong in there!)
- assign Track Number meta tags to all tracks
- assign Disc Number meta tags to all tracks of a multi-disc album
The “compilation” meta tag from iTunes is not used.
