Q: Is there a simple way to find out what playlists a particular song is a member of?
A: There sure is, and in typical Apple fashion, it’s almost too easy to notice it. Simply right-click on any song anywhere in iTunes, and highlight the “Show in Playlist” item. Here, a list is created of the playlists that the song is found in: click any of these, and you’ll jump to the appropriate position in that playlist.
Notice also the “Add to Playlist” button, which is a simple alternative to dragging and dropping tracks onto the playlist icons in the “Source” column.