Further experimentation seems to indicate that Album Artist has no effect whatsoever on the inferred "Mix Album" field. Is that correct? If so then I do not understand Matt's comment last year at all.
To help you understand Matt's comments I'll use 2 albums from my collection - Alan Jackson's "The Greatest Hits Collection" and "Greatest Hits Volume II"
For both Albums the [Album Artist] is Alan Jackson.
For "The Greatest Hits Collection" Alan Jackson is the [Artist] for every track, therefore MC does not consider it a "Mix Album" because [Artist] is = [Album Artist] for every track.
But for "The Greatest Hits Collection" Alan Jackson is the [Artist] for 17 tracks but for the other track the [Artist] is Alan Jackson and Jimmy Buffett, because there is an instance of [Artist] is NOT = [Album Artist] MC, quite correctly, considers it a "Mix Album" and records/stores that information for every track on the album.
Another reason why [Album Artist] is taken into consideration/used throughout MC is down to the Undeniable Fact that Album Names are not always Unique. I have qute a few Albums in my Library where the Album Name is the same but the Album Artist is different.
I.E. 6 Albums whose [Album] field/tag contains "Greatest Hits" but the [Album Artist] for each Album is different; in some parts/areas of MC all 6 are considered to be a single Album because at that point MC is only using the [Album] field/tag.
I've also got more than 1 occurence where the Same [Artist]/[Album Artist] has recorded 2 very different Albums that have the Same Album Name, thankfully they were always released in different years which allows me to De-Duplicate the Album Name.
Just to be clear: this is true only when the tracks are all in the same folder on disc - correct? If the files are stored in different folders, this logic does not apply. (There is otherwise no rule about files from the same album having to be in the same folder...)
MC doesn't care if the Tracks for an Album are in the Same Folder or Different Folders, as far as MC is concerned an Album is an entity, in its Library/Database, where the [Album] and [Album Artist] fields/tags contain the same Information/Data regardless of where they are located on the device the albums tracks are stored on.
Not sure I understand this. There are plenty of tags which optionally exist in a file but which MC uses if they are present. Movement, Month, Total Discs, all can be used by MC but are not always present. Why can't MC use the Compilation flag if it's present?
One of the things the MC Expression Language is incapable of doing is to test to see if a Field/Tag Exists, therefore if I wrote a test that uses the content of s field/tag that only exists on my installation it would not work on your installation.
Movement, Month, Total Discs, and most of the other MC provided fields/tags, are only Optional in respect of their being Used - They Can Not be Modified or Deleted by the User.
The only fields/tags that Optionally Exist are the ones that are added by Individual Users.
