I have searched high and low and cannot find a solution (maybe one does't exist yet). My iTunes library is roughly 250GB so I have moved it to an external HDD which I have attached to the Time Capsule. I have pointed the iTunes on my MacBook Air to this external HDD and manage to sync my music and apps to my iPhone and iPad.

My brother also has a MacBook and iPhone. As the iTunes library remains on an external HDD, I wondered if there was a way to point his MacBook to this iTunes library in order to sync the music and apps of his choice independent of how I sync music and apps from my MacBook to iPhone.

Now, I understand that when one Mac is using the the iTunes library on an external HDD, it cannot be accessed by another user. This is fine. So, what would happen when I add new apps, music, videos, podcasts etc. to the iTunes library on the external HDD (as I would be managing the media); would these changes be reflected once he opened iTunes on his MacBook? If not, how would I do so?

I suppose the aim is to maintain a central iTunes library on an external HDD (attached to the Time Capsule) in order for users to sync the content they want to their iDevices but most importantly be able to see new content once it is added to the library.

Thanks in advance and I hope I have explained this well enough .