I have the same problem? I have found out that the migrated files cause a new user to be set up . You have to go to your system preferences icon ( the black & white one with gears) open it up and clic on users & groups under title of System. In there you have to unlock the lock and go to the newly created user I think it shows up as a house. Clic on that and your system will change to that new user. Your files will be in this new users files. I found mine this way but even though I found them I still cannot move or transfer them into my I-Mac I-Tunes program.
If anyone knows how we can do that we would be very thankful