Okay, so this is beyond frustrating. I have iTunes running on my Mac (El Capitan). I have an iPhone 7 Plus. I'm syncing a number of iTunes playlists to my iPhone. I add a song (or multiple songs) to one of the playlists, then sync my iPhone. At this point, those songs are deleted from that playlist on my Mac and do not get sync'd to my iPhone 7. So, then I re-add those songs (which sucks because I already fixed the name, artist and artwork the first time around and I have to redo that) and sync again. This time it ACTUALLY adds the songs to the iPhone. So frustrating! I used to be able to add songs to a playlist on my computer, and those songs would sync to my iPhone. Ever since Apple Music and the Cloud decided to take dominance, my music doesn't sync very easily anymore. I have no interest in using iTunes Cloud or Apple Music. I just wanna sync MY music to MY phone from MY playlists. In the old days, this used to work 100% of the time. Now it's just a mess.