When restarting with OS X Maverick, i was asked to sign in with our apple id. We have one old apple id for our imac and another for the ipad. My husband is not sure of the password for the first id. I did not sign in, for fear that all of my old purchases would be lost, but not sure if that would even be the case. how do i combine without losing my music? Would like to switch both to the id for the ipad, so we can use icloud to listen to music.