As I usually buy the most music, my iTunes is the "master" iTunes in the house with all of our tunes stored on an external hard disk. While my spouse can stream the music from my computer, he cannot create playlists or put any of the music on his iPod. I know I could simply copy all of the tunes on my computer to his computer and simply authorize his computer to play my tunes. But, then we have to maintain 2 copies of the music, which seems very counter-productive. Is there any I can share my tunes with my spouse without having to make multiple copies of our entire library?