Well, Grip's multi-artist feature doesn't change the Disc Artist tag, it just adds artist infor to the track name. I have Grip configured to create music directories based on Artist/Album, so all of this music would wind up under "Various".

I just double checked some of my rips i still have on my PC. Disc artist isn't changed, because there is nothing sensible you could change it too, apart from what is grabbed from the freedb.

However the important part is, with multi artist enabled, the ID3 Artist tag is set to the Track artist, the disc artist field isn't actually used, as there is no ID3v1 tag for it, the only place it is used is if you have told grip to place the MP3s in a directory structure based on the album artist name.

It does not add artist info to the track name.

I usually set the disc artist to the name of the compilation series ( i don't have any soundtracks) So grip will place compilations in a directory structure like

/Gathering/The Gathering
/Gathering/Gathering 2
/Gathering/Gathering 99

So Gathering is the disc artist, Gathering 99 is the album name, but all the songs won't have Gathering as the artist, they will have the actual artist set in their ID3 tag.

Note that you can customise allot of this, %A is the artist of the current disc, and %a is the artist of the current track. So you could probably have each track in it's own directory if you really wanted by specifing the destination directory as %a instead of %A.