Various Artists logic
From SqueezeboxWiki
Squeezebox Server, or Logitech Media Server, both use an internal logic to determine if something scanned in is a compilation, or not.
This internal logic is only triggered if a given album has one or more 'artist mismatches' between tracks, and no ALBUMARTIST tags, and no explicit COMPILATION tags.
otherwise:
If a file has explicit 'COMP=1' tags the server recognizes, it will ALWAYS be classified as a comp/VA album.
If a file has explicit 'COMP=0' tags the server recognizes, it will NEVER be classified as a comp/VA album.
If a file has explicit 'ALBUMARTIST' tags the server recognizes, it will NEVER be classified as a comp/VA album, UNLESS it ALSO has COMP=1 tags.
So, you can use an explicit COMPILATION tag to identify Compilation status (the COMPILATION=1 tag identifies the track as belonging to a compilation) to the server, and over-ride other tags. Take note that the server only reads tags and files and notes their location, and interprets all that info; it does NOT write to files or tags or move files.
for id3 tag type files, like mp3 and wma, the comp frame used is either TCMP or TXXX COMPILATION.
TPE2 or TXXX ALBUMARTIST or TXXX ALBUM ARTIST is used for ALBUMARTIST values. in the server settings, you want to be sure the server is "treating" the TPE2 value the way you want it to. (it can represent either 'album artist' or 'band' but the default is 'album artist' and thats the de facto standard that all apps use basically, so thats recommended)
for Vorbis tag type files, like FLAC and Ogg, the field used for comps is just COMPILATION; and ALBUMARTIST [or ALBUM ARTIST] for, you guessed it, ALBUMARTIST.
if you need a good tag editor, consider:
or
puddletag
NOTES:
be sure to look at the other options in the server for compilation handling, but strictly speaking, the VA classification logic is separate from those other options. the VA logic is essentially covered above, and its purpose is to just classify something as a comp, or not, to the server. how that classification is then handled and employed, is a separate matter.
As a practical matter, its a good idea to rescan after tag changes, but rescanning for "new and changed" music does not always work so it is better to "clear library and rescan everything" and even better to just stop slimserver, delete the cache, and restart, scanning from scratch.
While supported, it is not typical or recommended to use Comp=0 tags, they are almost never necessary. they often produce unexpected results or undesired behavior. [someone please describe here the justified usage case. i think it has something to do with files from the same album in different folders and the greatest hits logic]
for more info on comp handling, display, and settings, see Compilations
please note that if you don't see your comps under Home>Artists>Various Artists it is likely due to bug 9523:
http://bugs.slimdevices.com/show_bug.cgi?id=9523
...and the best fix for bug 9523 is bug 15604:
http://bugs.slimdevices.com/show_bug.cgi?id=15604
please show your support and vote for those bugs!
EXAMPLES:
If an album has the following tag values, (represented by 3 character variables), it will NOT be classified as a Compilation by the Server:
Album= ZZZ
Track 1 ARTIST= AAA
Track 2 ARTIST= AAA
Track 3 ARTIST= AAA
Track 4 ARTIST= AAA
etc...
All the tracks have the same artist so ergo, not a comp.
OR
Album= ZZZ
Track 1 ARTIST= AAA
Track 2 ARTIST= BBB
Track 3 ARTIST= CCC
Track 4 ARTIST= DDD
but all above also have:
ALBUMARTIST= XXX
The album will be sorted under artist XXX and will NOT be a Compilation, due to the ALBUMARTIST tag. No matter what the individual track artists are, if there is a common ALBUMARTIST on all tracks then the album is NOT a compilation. Whether the server recognizes your mp3s' ALBUMARTIST tags, if they exist, may be related to how the TPE2 tag is treated at scan time by the server.
Here are examples of albums SBS WILL classify as a compilation:
Album= YYY
Track 1 ARTIST= AAA & BBB
Track 2 ARTIST= AAA
Track 3 ARTIST= AAA
Track 4 ARTIST= AAA
Track 1 creates the artist "mismatch" on the album.
OR
Album= YYY
Track 1 ARTIST= AAA
Track 1 ARTIST= BBB
Track 2 ARTIST= AAA
Track 3 ARTIST= AAA
Track 1 is either using a "separator character" or "multiple tag frames/fields" to list more than one artist, so this creates the artist mismatch on the album.
The following are special cases of albums SBS will NOT identify as compilations:
Album= YYY
Track 1 ARTIST= Various Artists
Track 2 ARTIST= Various Artists
Track 3 ARTIST= Various Artists
Track 4 ARTIST= Various Artists
Tagging an album with ARTIST= Various Artists does NOT make the album a compilation, because there is no mismatch and currently the server does not recognize the meaning of the string.
The same would be true if you had ALBUMARTIST= Various Artists b/c there is no string recognition, and because the presence of ANY ALBUMARTIST values means the server will classify it as not a comp.
Be aware, that those strings will make you fall victim to the bugs mentioned earlier, so you should add Comp=1 tags or use another workaround mentioned in the bugs and elsewhere.
The following album tagging also will not result in a comp:
Album= YYY
Track 1 ARTIST= AAA
Track 1 ARTIST= BBB
Track 2 ARTIST= AAA
Track 2 ARTIST= BBB
Track 3 ARTIST= AAA
Track 3 ARTIST= BBB
If an album has the same set of multiple artists on every track it is not a compilation, b/c there is no artist mismatching amongst the tracks, and thus should appear under each artist.
REMEMBER: you can always FORCE classification, one way or the other, using explicit Comp=1 or Comp=0 tags!
