I don't like to be so negative but this feature is totally broken for me. I signed up for Apple Music and selected the family plan, completed the transaction and everything works great on my phone. The rest of my family....not so much :-(. When anyone else in the family starts the music app they are prompted to sign up for a new plan even though they are logged in with their own ID which is recognized in both iCloud family and iTunes/app store as valid and a part of the family. They select "already a member" at the music app splash screen, enter the correct credentials but the service is not enabled. They only have access to their local music. I have called and worked with apple support this entire week to try to fix the issue but it is still broken. They are researching. I'm confident it will be resolved eventually but am curious if anyone has this working correctly? If so, did you do anything differently than I did above?