I have an iMac, iPhone, and iPad, and they are all connected with iTunes from the iMac, if I buy music on any one device, it automatically downloads to the other two--doesn't just stay in iCloud (I don't have a lot of music, and I do have a lot of storage on all three devices. I also have a 2015 Retina MacBook, that is not connected to the other three with iTunes (I don't see a way to do that?). I do have the same iTunes Store Apple ID for all four devices, so, when I buy any music from any of the four devices it appears on the other three...however, the music NEVER automatically downloads to the MacBook...as I found out while traveling and trying to play music on a plane...nothing there to play, since it all had to be downloaded from iCloud. Oddly enough, when I buy music on the MacBook, it DOES appear and download on the other three devices, just not the other way around. What do I need to do to get the MacBook to fully sync and download my music when purchased on the other devices? Thanks!