I'm using the Album Artist field when an album has tracks performed by various artists. I also use it so that Tribute Albums can be seen with the ones belonging to the respective tributee artists.
I'm gonna put some examples.
Album Title: "Philadelphia: Music From The Motion Picture"
Track listing:
1. Streets of Philadelphia - Bruce Springsteen
2. Lovetown - Peter Gabriel
3. It's in Your Eyes - Pauletta Washington
4. Ibo Lele (Dreams Come True) - RAM
5. Please Send Me Someone to Love - Sade
6. Have You Ever Seen the Rain? - Spin Doctors
7. I Don't Wanna Talk About It - Indigo Girls
8. Mamma Morta - Maria Callas
9. Philadelphia - Neil Young
In the above example, I fill the Artist field of each track with the name of its performer, i.e. Bruce Springsteen, Indigo Girls, etc. and in the "Album Artist" field of each song I put "Compilations - Soundtrack" (you could also fill it as "Various Artists" or "Various Artists - Soundtracks" or whatever suits best your needs).
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Album Title: "Badlands: A Tribute To Bruce Springsteen's Nebraska"
Track listing:
1. Nebraska - Chrissie Hynde And Adam Seymour
2. Atlantic City - Hank III
3. Mansion On The Hill - Crooked Fingers (Eric Bachman, ex Archers of Loaf)
4. Johnny 99 - Los Lobos
5. Highway Patrolman - Dar Williams
6. State Trooper - Deanna Carter
7. Used Cars - Ani DiFranco
8. Open All Night - Son Volt
9. My Father's House - Ben Harper
10. Reason To Believe - Aimee Mann And Michael Penn
11. I'm On Fire - Johnny Cash (Bonus Track)
12. Downbound Train - Raul Malo of the Mavericks (Bonus Track)
13. Wages Of Sin - Damien Jurado And Rose Thomas (Bonus Track)
In this second example, the Artist field is filled with the performer of each song but in the "Album Artist" I fill "Bruce Springsteen".
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Now, let's see how MC processes the information:
I have some view schemes for browsing artists and albums where the "Album Artist" field plays an important role:
1.-
Artist/AlbumFields used: Album Artist (auto), Album
Now, when I browse this view scheme #1 and get to the artist "Bruce Springsteen" I see all the tracks belonging to his own albums plus the tribute albums, such as "Badlands: A Tribute To Bruce Springsteen's Nebraska", "Hometown: String Quartet Tribute to Springsteen", "Bruce Springsteen Tribute: Made in the U.S.A.", etc.... those latter not even have a single track performed by Springsteen but I want to keep them together with Springsteen's albums.
2.-
All ArtistsFields used: Artist, Album
When browsing this view scheme, under Bruce Springsteen I find all the tracks performed by him... the ones from his albums plus the albums where there is at least one track performed by him. In thumbnail grouped view I see nice covers of The River, Tom Joad, Born to Run, Nebraska, etc... plus Philadelphia OST, Dead Man Walking OST, America a Tribute to Heroes, etc.
Obviously, in this view scheme #2 browsing Ani DiFranco or Ben Harper I will find the tracks belonging to the album "Badlands tribute...."
3.-
CompilationsFields used: Album Artist (Auto), Album
Search Criteria: Album Artist: Compilations...
This is a view scheme that shows me some 10-12 entries, named for instance:
Compilations - Blues
Compilations - Country
Compilations - Electronica
Compilations - Jazz
Compilations - Pop/Rock
Compilations - Soul/R&B
Compilations - Soundtracks
etc.
Under each entry I find all the albums where I have filled the "Album Artist" field with "Compilations - (Something)", and therefore under "Compilations - Soundtracks" I will find all thouse soundtrack albums performed by various artists, and under "Compilations Pop/Rock" I will find albums such as "America, a Tribute....", "1999 Grammy Nominees", "Live on Letterman", etc. etc.
Finally, when several albums share the same title, such as "Greatest Hits", "Unplugged", "Best Of", etc. I've found that setting the same value in "Artist" and "Album Artist" makes that every album is assigned to his right performer in my view scheme #1 above, instead of being put altogether.
Of course, there will be many other applications to this "Album Artist" thing or other ways to do it, but it's something that has been very helpful for me in MJ/MC.
Sorry for the long post and the lack of screenshots
Hope it has been of help.
Thank you.
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Listening to: 'My City Of Ruin' from 'America: A Tribute To Heroes (CD1)' by 'Bruce Springsteen' on Media Center 9.0