Not sure if this is intended behaviour as some sort of DRM thing or a bug, however any songs I have downloaded for Offline Playback from Apple Music service need an internet connection to play. Example iPhone has dropped signal and I attempt to play an Apple Music song it will not start to play until signal is back, however once its got a signal it will play as normal from then on even when put into Airplane mode and other songs play as normal. If you try to start a song in Airplane mode it throws up a message saying Apple Music songs can't be played, however if you turn off Airplane mode and start to play songs and then turn Airplane mode back on then the rest will play as normal. I think this is just a bug, or rather I HOPE this is just a bug as this could be a problem with people going off the grid for a while for whatever reason (foreign trip with no data roaming, trip to rural area with no signal etc) Also this ONLY effects Apple Music downloads, your existing music downloaded for offline playback play as normal regardless of data connection. Anyone else experience this issue?