Sorry if this has been covered (I'm a new member). I just wanted to share a solution I've dreamed up for preventing the accumulation of duplicate files. In this case I mean duplicate versions of the same recording by the same artist: the sort of duplication that occurs when a song exists on the original cd/album and any of the following:
1) greatest hits CD
2) movie soundtrack
3) multi-artist compilation disk
Here's what I did ...
1) created three Playlist folders
Playlist Folder 1 = *greatest hits
Playlist Folder 2 = **soundtracks
Playlist Folder 3 = ***other compilations
2) add the appropriate one, two, or three asterisks to the end of an album title. For example: "ZZ Top's Greatest Hits*". The presence of asterisks tells me to go to the album title in the corresponding playlist folder instead.
3) since I also have ZZ Top's "Eliminator" album, I deleted the "Eliminator" songs in the "ZZ Top's Greatest Hits*" album folder.
4) create a playlist in Folder 1 called "ZZ Top's Greatest Hits". Recreate the complete contents of ZZ Top's Greatest Hits by pulling in the songs from both CDs. The final playlist contains the complete contents of ZZ Top's Greatest Hits, in the order that the songs occur on that CD, but all the "Eliminator" tracks come from the "Eliminator" album folder, while the rest come from the "ZZ Top's Greatest Hits*" album folder. In the end, the songs "Legs" and "Sharp-dressed Man" only exist once in my library, rather than twice.