A Google search has told me that many people have had problems syncing with iTunes (with most concluding that iTunes is basically a Jack of all trades, and master of none). The problem I have is that when I add new songs to a playlist, the updated playlist doesn't sync to my iPhone. What I see as the most salient points are that: 1) the playlist is not very big (29 tracks) 2) all tracks are purchased from iTunes (and have been purchased in the past year as new releases, i.e. I'm not adding tracks from an obscure album that is no longer on iTunes). 3) I'm using the most up-to-date versions of iOS (iPhone 6s) and El Capitan (late 2012 mac mini) 4) My iTunes library is on an external drive (I have close to 900GB of movies which would fill my hard drive) 5) I've tried deleting / rebuilding my iTunes library on several occasions, and the playlists all sync wonderfully, however as soon as I purchase a new track and add it, the update doesn't sync to my iPhone. 6) I don't use iTunes match or iTunes music, as both have completely screwed up my iTunes library in the past, and they are more hassle than they are worth (especially as they are paid for services). I know other people have had similar problems, but I've yet to find anyone post a solution that is more than a temporary fix (hence the re-doing my library several times). I've been tried updating the playlist on my phone to see if it will sync back to the computer, and it does, but as a different playlist (with a "1" appended to the name). Unfortunately, that playlist also seems to be missing random tracks when synced to the computer..... Apparently there is a new version of iTunes coming soon, but I won't be holding my breath that it will be any better. So I'm wondering has anyone who has had this type of issue been able to fix it?