That is a feature that would really come in handy for me. I have lost count of how many 2-CD sets Ive ripped into iTunes, and then have to create a separate playlist for each disc. It would be great from an organization point of view to be bale to create a playlist/folder just for the set, then have CD 1 and CD 2 sub-folders/playlists nested within that one. Same with albums from the same artist. Although I of course want a playlist for each album, it would be nice if I could group all 12 of my Tower of Power albums, just as a example, into a Tower of Power playlist/folder and have each album listed within that. Basically it would be nice simply from an organizing and aesthetics points of view if nothing else...