I usually use iTunes to manage my music and playlists. With iTunes if I try to add a song that's already in a playlist I get a popup telling me. The other day I was adding a few songs to playlists using my phone. I think this was the first time I'd done it that way. I caught myself thinking "I'm surprised that song wasn't already in that playlist" and when I went to check, it was, but it let me add the song again (so it shows up twice). Just curious if anyone knows if this is a bug in iOS9 or if it's always been that way.